轉載請註明出處：http://blog.csdn.net/linglongxin24/article/details/53750584
本文出自【DylanAndroid的部落格】
玩轉JDBC打造資料庫操作萬能工具類JDBCUtil，加入了高效的資料庫連線池，利用了引數繫結有效防止SQL隱碼攻擊
在之前學習了MySQL和Oracle之後，那麼，如和在Java種去連線這兩種資料庫。在這個輕量級的工具類當中，使用了資料庫連線池
去提高資料庫連線的高效性，並且使用了PreparedStatement來執行對SQL的預編譯，能夠有效防止SQL隱碼攻擊問題。
一.準備在配置檔案配置:配置資料庫連線屬性檔案：在專案新建config包下建立jdbc-mysql.properties並加入以下配置
jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/test?characterEncoding=utf8
jdbc.username=root
jdbc.password=root複製程式碼二.準備資料庫連線池物件：單例
package util;
import com.mchange.v2.c3p0.ComboPooledDataSource;
import com.mchange.v2.c3p0.DataSources;
import java.beans.PropertyVetoException;
import java.io.FileInputStream;
import java.io.IOException;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;
/**
* 資料庫連線物件
* Created by yuandl on 2016-12-16.
*/
public class DBConnectionPool {
private static volatile DBConnectionPool dbConnection;
private ComboPooledDataSource cpds;
/**
* 在建構函式初始化的時候獲取資料庫連線
*/
private DBConnectionPool() {
try {
/**通過屬性檔案獲取資料庫連線的引數值**/
Properties properties = new Properties();
FileInputStream fileInputStream = new FileInputStream("src/config/jdbc-mysql.properties");
properties.load(fileInputStream);
/**獲取屬性檔案中的值**/
String driverClassName = properties.getProperty("jdbc.driverClassName");
String url = properties.getProperty("jdbc.url");
String username = properties.getProperty("jdbc.username");
String password = properties.getProperty("jdbc.password");
/**資料庫連線池物件**/
cpds = new ComboPooledDataSource();
/**設定資料庫連線驅動**/
cpds.setDriverClass(driverClassName);
/**設定資料庫連線地址**/
cpds.setJdbcUrl(url);
/**設定資料庫連線使用者名稱**/
cpds.setUser(username);
/**設定資料庫連線密碼**/
cpds.setPassword(password);
/**初始化時建立的連線數,應在minPoolSize與maxPoolSize之間取值.預設為3**/
cpds.setInitialPoolSize(3);
/**連線池中保留的最大連線資料.預設為15**/
cpds.setMaxPoolSize(10);
/**當連線池中的連線用完時，C3PO一次性建立新的連線數目;**/
cpds.setAcquireIncrement(1);
/**隔多少秒檢查所有連線池中的空閒連線,預設為0表示不檢查;**/
cpds.setIdleConnectionTestPeriod(60);
/**最大空閒時間,超過空閒時間的連線將被丟棄.為0或負資料則永不丟棄.預設為0;**/
cpds.setMaxIdleTime(3000);
/**因效能消耗大請只在需要的時候使用它。如果設為true那麼在每個connection提交的
時候都將校驗其有效性。建議使用idleConnectionTestPeriod或automaticTestTable
等方法來提升連線測試的效能。Default: false**/
cpds.setTestConnectionOnCheckout(true);
/**如果設為true那麼在取得連線的同時將校驗連線的有效性。Default: false **/
cpds.setTestConnectionOnCheckin(true);
/**定義在從資料庫獲取新的連線失敗後重復嘗試獲取的次數，預設為30;**/
cpds.setAcquireRetryAttempts(30);
/**兩次連線中間隔時間預設為1000毫秒**/
cpds.setAcquireRetryDelay(1000);
/** 獲取連線失敗將會引起所有等待獲取連線的執行緒異常,
但是資料來源仍有效的保留,並在下次呼叫getConnection()的時候繼續嘗試獲取連線.如果設為true,
那麼嘗試獲取連線失敗後該資料來源將申明已經斷開並永久關閉.預設為false**/
cpds.setBreakAfterAcquireFailure(true);
} catch (IOException e) {
e.printStackTrace();
} catch (PropertyVetoException e) {
e.printStackTrace();
}
}
/**
* 獲取資料庫連線物件，單例
*
* @return
*/
public static DBConnectionPool getInstance() {
if (dbConnection == null) {
synchronized (DBConnectionPool.class) {
if (dbConnection == null) {
dbConnection = new DBConnectionPool();
}
}
}
return dbConnection;
}
/**
* 獲取資料庫連線
*
* @return 資料庫連線
*/
public final synchronized Connection getConnection() throws SQLException {
return cpds.getConnection();
}
/**
* finalize()方法是在垃圾收集器刪除物件之前對這個物件呼叫的。
*
* @throws Throwable
*/
protected void finalize() throws Throwable {
DataSources.destroy(cpds);
super.finalize();
}
}複製程式碼三.實現新增、修改、刪除、查詢操作的兩個核心方法：可以實現任何複雜的SQL,而且通過資料繫結的方式不會有SQL隱碼攻擊問題
/**
* 可以執行新增，修改，刪除
*
* @param sql sql語句
* @param bindArgs 繫結引數
* @return 影響的行數
* @throws SQLException SQL異常
*/
public static int executeUpdate(String sql, Object[] bindArgs) throws SQLException {
/**影響的行數**/
int affectRowCount = -1;
Connection connection = null;
PreparedStatement preparedStatement = null;
try {
/**從資料庫連線池中獲取資料庫連線**/
connection = DBConnectionPool.getInstance().getConnection();
/**執行SQL預編譯**/
preparedStatement = connection.prepareStatement(sql.toString());
/**設定不自動提交，以便於在出現異常的時候資料庫回滾**/
connection.setAutoCommit(false);
System.out.println(getExecSQL(sql, bindArgs));
if (bindArgs != null) {
/**繫結引數設定sql佔位符中的值**/
for (int i = 0; i < bindArgs.length; i++) {
preparedStatement.setObject(i + 1, bindArgs[i]);
}
}
/**執行sql**/
affectRowCount = preparedStatement.executeUpdate();
connection.commit();
String operate;
if (sql.toUpperCase().indexOf("DELETE FROM") != -1) {
operate = "刪除";
} else if (sql.toUpperCase().indexOf("INSERT INTO") != -1) {
operate = "新增";
} else {
operate = "修改";
}
System.out.println("成功" + operate + "了" + affectRowCount + "行");
System.out.println();
} catch (Exception e) {
if (connection != null) {
connection.rollback();
}
e.printStackTrace();
throw e;
} finally {
if (preparedStatement != null) {
preparedStatement.close();
}
if (connection != null) {
connection.close();
}
}
return affectRowCount;
}
/**
* 執行查詢
*
* @param sql 要執行的sql語句
* @param bindArgs 繫結的引數
* @return List<Map<String, Object>>結果集物件
* @throws SQLException SQL執行異常
*/
public static List<Map<String, Object>> executeQuery(String sql, Object[] bindArgs) throws SQLException {
List<Map<String, Object>> datas = new ArrayList<>();
Connection connection = null;
PreparedStatement preparedStatement = null;
ResultSet resultSet = null;
try {
/**獲取資料庫連線池中的連線**/
connection = DBConnectionPool.getInstance().getConnection();
preparedStatement = connection.prepareStatement(sql);
if (bindArgs != null) {
/**設定sql佔位符中的值**/
for (int i = 0; i < bindArgs.length; i++) {
preparedStatement.setObject(i + 1, bindArgs[i]);
}
}
System.out.println(getExecSQL(sql, bindArgs));
/**執行sql語句，獲取結果集**/
resultSet = preparedStatement.executeQuery();
getDatas(resultSet);
System.out.println();
} catch (Exception e) {
e.printStackTrace();
throw e;
} finally {
if (resultSet != null) {
resultSet.close();
}
if (preparedStatement != null) {
preparedStatement.close();
}
if (connection != null) {
connection.close();
}
}
return datas;
}複製程式碼四.執行新增的簡化操作
/**
* 執行資料庫插入操作
*
* @param valueMap 插入資料表中key為列名和value為列對應的值的Map物件
* @param tableName 要插入的資料庫的表名
* @return 影響的行數
* @throws SQLException SQL異常
*/
public static int insert(String tableName, Map<String, Object> valueMap) throws SQLException {
/**獲取資料庫插入的Map的鍵值對的值**/
Set<String> keySet = valueMap.keySet();
Iterator<String> iterator = keySet.iterator();
/**要插入的欄位sql，其實就是用key拼起來的**/
StringBuilder columnSql = new StringBuilder();
/**要插入的欄位值，其實就是？**/
StringBuilder unknownMarkSql = new StringBuilder();
Object[] bindArgs = new Object[valueMap.size()];
int i = 0;
while (iterator.hasNext()) {
String key = iterator.next();
columnSql.append(i == 0 ? "" : ",");
columnSql.append(key);
unknownMarkSql.append(i == 0 ? "" : ",");
unknownMarkSql.append("?");
bindArgs[i] = valueMap.get(key);
i++;
}
/**開始拼插入的sql語句**/
StringBuilder sql = new StringBuilder();
sql.append("INSERT INTO ");
sql.append(tableName);
sql.append(" (");
sql.append(columnSql);
sql.append(" ) VALUES (");
sql.append(unknownMarkSql);
sql.append(" )");
return executeUpdate(sql.toString(), bindArgs);
}複製程式碼五.執行更新的簡化操作
/**
* 執行更新操作
*
* @param tableName 表名
* @param valueMap 要更改的值
* @param whereMap 條件
* @return 影響的行數
* @throws SQLException SQL異常
*/
public static int update(String tableName, Map<String, Object> valueMap, Map<String, Object> whereMap) throws SQLException {
/**獲取資料庫插入的Map的鍵值對的值**/
Set<String> keySet = valueMap.keySet();
Iterator<String> iterator = keySet.iterator();
/**開始拼插入的sql語句**/
StringBuilder sql = new StringBuilder();
sql.append("UPDATE ");
sql.append(tableName);
sql.append(" SET ");
/**要更改的的欄位sql，其實就是用key拼起來的**/
StringBuilder columnSql = new StringBuilder();
int i = 0;
List<Object> objects = new ArrayList<>();
while (iterator.hasNext()) {
String key = iterator.next();
columnSql.append(i == 0 ? "" : ",");
columnSql.append(key + " = ? ");
objects.add(valueMap.get(key));
i++;
}
sql.append(columnSql);
/**更新的條件:要更改的的欄位sql，其實就是用key拼起來的**/
StringBuilder whereSql = new StringBuilder();
int j = 0;
if (whereMap != null && whereMap.size() > 0) {
whereSql.append(" WHERE ");
iterator = whereMap.keySet().iterator();
while (iterator.hasNext()) {
String key = iterator.next();
whereSql.append(j == 0 ? "" : " AND ");
whereSql.append(key + " = ? ");
objects.add(whereMap.get(key));
j++;
}
sql.append(whereSql);
}
return executeUpdate(sql.toString(), objects.toArray());
}複製程式碼六.執行刪除的簡化操作
/**
* 執行刪除操作
*
* @param tableName 要刪除的表名
* @param whereMap 刪除的條件
* @return 影響的行數
* @throws SQLException SQL執行異常
*/
public static int delete(String tableName, Map<String, Object> whereMap) throws SQLException {
/**準備刪除的sql語句**/
StringBuilder sql = new StringBuilder();
sql.append("DELETE FROM ");
sql.append(tableName);
/**更新的條件:要更改的的欄位sql，其實就是用key拼起來的**/
StringBuilder whereSql = new StringBuilder();
Object[] bindArgs = null;
if (whereMap != null && whereMap.size() > 0) {
bindArgs = new Object[whereMap.size()];
whereSql.append(" WHERE ");
/**獲取資料庫插入的Map的鍵值對的值**/
Set<String> keySet = whereMap.keySet();
Iterator<String> iterator = keySet.iterator();
int i = 0;
while (iterator.hasNext()) {
String key = iterator.next();
whereSql.append(i == 0 ? "" : " AND ");
whereSql.append(key + " = ? ");
bindArgs[i] = whereMap.get(key);
i++;
}
sql.append(whereSql);
}
return executeUpdate(sql.toString(), bindArgs);
}複製程式碼七.查詢的4種玩法
1.執行sql通過 Map
限定查詢條件查詢 /** * 1..執行sql通過 Map<String, Object>限定查詢條件查詢 * * @param tableName 表名 * @param whereMap where條件 * @return List<Map<String, Object>> * @throws SQLException */ public static List<Map<String, Object>> query(String tableName, Map<String, Object> whereMap) throws SQLException { String whereClause = ""; Object[] whereArgs = null; if (whereMap != null && whereMap.size() > 0) { Iterator<String> iterator = whereMap.keySet().iterator(); whereArgs = new Object[whereMap.size()]; int i = 0; while (iterator.hasNext()) { String key = iterator.next(); whereClause += (i == 0 ? "" : " AND "); whereClause += (key + " = ? "); whereArgs[i] = whereMap.get(key); i++; } } return query(tableName, false, null, whereClause, whereArgs, null, null, null, null); }複製程式碼2.執行sql條件引數繫結形式的查詢
/** * 2.執行sql條件引數繫結形式的查詢 * * @param tableName 表名 * @param whereClause where條件的sql * @param whereArgs where條件中佔位符中的值 * @return List<Map<String, Object>> * @throws SQLException */ public static List<Map<String, Object>> query(String tableName, String whereClause, String[] whereArgs) throws SQLException { return query(tableName, false, null, whereClause, whereArgs, null, null, null, null); }複製程式碼3.包含所有的查詢條件的查詢方法
/** * 執行全部結構的sql查詢 * * @param tableName 表名 * @param distinct 去重 * @param columns 要查詢的列名 * @param selection where條件 * @param selectionArgs where條件中佔位符中的值 * @param groupBy 分組 * @param having 篩選 * @param orderBy 排序 * @param limit 分頁 * @return List<Map<String, Object>> * @throws SQLException */ public static List<Map<String, Object>> query(String tableName, boolean distinct, String[] columns, String selection, Object[] selectionArgs, String groupBy, String having, String orderBy, String limit) throws SQLException { String sql = buildQueryString(distinct, tableName, columns, selection, groupBy, having, orderBy, limit); return executeQuery(sql, selectionArgs); }複製程式碼- 4.通過單純的sql查詢資料,慎用，會有sql注入問題，只是為了方便查詢，實際開發中不會去使用這個方法
* 4.通過sql查詢資料, * 慎用，會有sql注入問題只是為了方便查詢，實際開發中不會去使用這個方法 * * @param sql * @return 查詢的資料集合 * @throws SQLException */ public static List<Map<String, Object>> query(String sql) throws SQLException { return executeQuery(sql, null); }複製程式碼八.DBUtil的完整程式碼
package util;
import com.sun.istack.internal.Nullable;
import java.sql.*;
import java.util.*;
import java.util.regex.Pattern;
/**
* 資料庫JDBC連線工具類
* Created by yuandl on 2016-12-16.
*/
public class DBUtil {
/**
* 執行資料庫插入操作
*
* @param valueMap 插入資料表中key為列名和value為列對應的值的Map物件
* @param tableName 要插入的資料庫的表名
* @return 影響的行數
* @throws SQLException SQL異常
*/
public static int insert(String tableName, Map<String, Object> valueMap) throws SQLException {
/**獲取資料庫插入的Map的鍵值對的值**/
Set<String> keySet = valueMap.keySet();
Iterator<String> iterator = keySet.iterator();
/**要插入的欄位sql，其實就是用key拼起來的**/
StringBuilder columnSql = new StringBuilder();
/**要插入的欄位值，其實就是？**/
StringBuilder unknownMarkSql = new StringBuilder();
Object[] bindArgs = new Object[valueMap.size()];
int i = 0;
while (iterator.hasNext()) {
String key = iterator.next();
columnSql.append(i == 0 ? "" : ",");
columnSql.append(key);
unknownMarkSql.append(i == 0 ? "" : ",");
unknownMarkSql.append("?");
bindArgs[i] = valueMap.get(key);
i++;
}
/**開始拼插入的sql語句**/
StringBuilder sql = new StringBuilder();
sql.append("INSERT INTO ");
sql.append(tableName);
sql.append(" (");
sql.append(columnSql);
sql.append(" ) VALUES (");
sql.append(unknownMarkSql);
sql.append(" )");
return executeUpdate(sql.toString(), bindArgs);
}
/**
* 執行更新操作
*
* @param tableName 表名
* @param valueMap 要更改的值
* @param whereMap 條件
* @return 影響的行數
* @throws SQLException SQL異常
*/
public static int update(String tableName, Map<String, Object> valueMap, Map<String, Object> whereMap) throws SQLException {
/**獲取資料庫插入的Map的鍵值對的值**/
Set<String> keySet = valueMap.keySet();
Iterator<String> iterator = keySet.iterator();
/**開始拼插入的sql語句**/
StringBuilder sql = new StringBuilder();
sql.append("UPDATE ");
sql.append(tableName);
sql.append(" SET ");
/**要更改的的欄位sql，其實就是用key拼起來的**/
StringBuilder columnSql = new StringBuilder();
int i = 0;
List<Object> objects = new ArrayList<>();
while (iterator.hasNext()) {
String key = iterator.next();
columnSql.append(i == 0 ? "" : ",");
columnSql.append(key + " = ? ");
objects.add(valueMap.get(key));
i++;
}
sql.append(columnSql);
/**更新的條件:要更改的的欄位sql，其實就是用key拼起來的**/
StringBuilder whereSql = new StringBuilder();
int j = 0;
if (whereMap != null && whereMap.size() > 0) {
whereSql.append(" WHERE ");
iterator = whereMap.keySet().iterator();
while (iterator.hasNext()) {
String key = iterator.next();
whereSql.append(j == 0 ? "" : " AND ");
whereSql.append(key + " = ? ");
objects.add(whereMap.get(key));
j++;
}
sql.append(whereSql);
}
return executeUpdate(sql.toString(), objects.toArray());
}
/**
* 執行刪除操作
*
* @param tableName 要刪除的表名
* @param whereMap 刪除的條件
* @return 影響的行數
* @throws SQLException SQL執行異常
*/
public static int delete(String tableName, Map<String, Object> whereMap) throws SQLException {
/**準備刪除的sql語句**/
StringBuilder sql = new StringBuilder();
sql.append("DELETE FROM ");
sql.append(tableName);
/**更新的條件:要更改的的欄位sql，其實就是用key拼起來的**/
StringBuilder whereSql = new StringBuilder();
Object[] bindArgs = null;
if (whereMap != null && whereMap.size() > 0) {
bindArgs = new Object[whereMap.size()];
whereSql.append(" WHERE ");
/**獲取資料庫插入的Map的鍵值對的值**/
Set<String> keySet = whereMap.keySet();
Iterator<String> iterator = keySet.iterator();
int i = 0;
while (iterator.hasNext()) {
String key = iterator.next();
whereSql.append(i == 0 ? "" : " AND ");
whereSql.append(key + " = ? ");
bindArgs[i] = whereMap.get(key);
i++;
}
sql.append(whereSql);
}
return executeUpdate(sql.toString(), bindArgs);
}
/**
* 可以執行新增，修改，刪除
*
* @param sql sql語句
* @param bindArgs 繫結引數
* @return 影響的行數
* @throws SQLException SQL異常
*/
public static int executeUpdate(String sql, Object[] bindArgs) throws SQLException {
/**影響的行數**/
int affectRowCount = -1;
Connection connection = null;
PreparedStatement preparedStatement = null;
try {
/**從資料庫連線池中獲取資料庫連線**/
connection = DBConnectionPool.getInstance().getConnection();
/**執行SQL預編譯**/
preparedStatement = connection.prepareStatement(sql.toString());
/**設定不自動提交，以便於在出現異常的時候資料庫回滾**/
connection.setAutoCommit(false);
System.out.println(getExecSQL(sql, bindArgs));
if (bindArgs != null) {
/**繫結引數設定sql佔位符中的值**/
for (int i = 0; i < bindArgs.length; i++) {
preparedStatement.setObject(i + 1, bindArgs[i]);
}
}
/**執行sql**/
affectRowCount = preparedStatement.executeUpdate();
connection.commit();
String operate;
if (sql.toUpperCase().indexOf("DELETE FROM") != -1) {
operate = "刪除";
} else if (sql.toUpperCase().indexOf("INSERT INTO") != -1) {
operate = "新增";
} else {
operate = "修改";
}
System.out.println("成功" + operate + "了" + affectRowCount + "行");
System.out.println();
} catch (Exception e) {
if (connection != null) {
connection.rollback();
}
e.printStackTrace();
throw e;
} finally {
if (preparedStatement != null) {
preparedStatement.close();
}
if (connection != null) {
connection.close();
}
}
return affectRowCount;
}
/**
* 通過sql查詢資料,
* 慎用，會有sql注入問題
*
* @param sql
* @return 查詢的資料集合
* @throws SQLException
*/
public static List<Map<String, Object>> query(String sql) throws SQLException {
return executeQuery(sql, null);
}
/**
* 執行sql通過 Map<String, Object>限定查詢條件查詢
*
* @param tableName 表名
* @param whereMap where條件
* @return List<Map<String, Object>>
* @throws SQLException
*/
public static List<Map<String, Object>> query(String tableName,
Map<String, Object> whereMap) throws SQLException {
String whereClause = "";
Object[] whereArgs = null;
if (whereMap != null & whereMap.size() > 0) {
Iterator<String> iterator = whereMap.keySet().iterator();
whereArgs = new Object[whereMap.size()];
int i = 0;
while (iterator.hasNext()) {
String key = iterator.next();
whereClause += (i == 0 ? "" : " AND ");
whereClause += (key + " = ? ");
whereArgs[i] = whereMap.get(key);
i++;
}
}
return query(tableName, false, null, whereClause, whereArgs, null, null, null, null);
}
/**
* 執行sql條件引數繫結形式的查詢
*
* @param tableName 表名
* @param whereClause where條件的sql
* @param whereArgs where條件中佔位符中的值
* @return List<Map<String, Object>>
* @throws SQLException
*/
public static List<Map<String, Object>> query(String tableName,
String whereClause,
String[] whereArgs) throws SQLException {
return query(tableName, false, null, whereClause, whereArgs, null, null, null, null);
}
/**
* 執行全部結構的sql查詢
*
* @param tableName 表名
* @param distinct 去重
* @param columns 要查詢的列名
* @param selection where條件
* @param selectionArgs where條件中佔位符中的值
* @param groupBy 分組
* @param having 篩選
* @param orderBy 排序
* @param limit 分頁
* @return List<Map<String, Object>>
* @throws SQLException
*/
public static List<Map<String, Object>> query(String tableName,
boolean distinct,
String[] columns,
String selection,
Object[] selectionArgs,
String groupBy,
String having,
String orderBy,
String limit) throws SQLException {
String sql = buildQueryString(distinct, tableName, columns, selection, groupBy, having, orderBy, limit);
return executeQuery(sql, selectionArgs);
}
/**
* 執行查詢
*
* @param sql 要執行的sql語句
* @param bindArgs 繫結的引數
* @return List<Map<String, Object>>結果集物件
* @throws SQLException SQL執行異常
*/
public static List<Map<String, Object>> executeQuery(String sql, Object[] bindArgs) throws SQLException {
List<Map<String, Object>> datas = new ArrayList<>();
Connection connection = null;
PreparedStatement preparedStatement = null;
ResultSet resultSet = null;
try {
/**獲取資料庫連線池中的連線**/
connection = DBConnectionPool.getInstance().getConnection();
preparedStatement = connection.prepareStatement(sql);
if (bindArgs != null) {
/**設定sql佔位符中的值**/
for (int i = 0; i < bindArgs.length; i++) {
preparedStatement.setObject(i + 1, bindArgs[i]);
}
}
System.out.println(getExecSQL(sql, bindArgs));
/**執行sql語句，獲取結果集**/
resultSet = preparedStatement.executeQuery();
getDatas(resultSet);
System.out.println();
} catch (Exception e) {
e.printStackTrace();
throw e;
} finally {
if (resultSet != null) {
resultSet.close();
}
if (preparedStatement != null) {
preparedStatement.close();
}
if (connection != null) {
connection.close();
}
}
return datas;
}
/**
* 將結果集物件封裝成List<Map<String, Object>> 物件
*
* @param resultSet 結果多想
* @return 結果的封裝
* @throws SQLException
*/
private static List<Map<String, Object>> getDatas(ResultSet resultSet) throws SQLException {
List<Map<String, Object>> datas = new ArrayList<>();
/**獲取結果集的資料結構物件**/
ResultSetMetaData metaData = resultSet.getMetaData();
while (resultSet.next()) {
Map<String, Object> rowMap = new HashMap<>();
for (int i = 1; i <= metaData.getColumnCount(); i++) {
rowMap.put(metaData.getColumnName(i), resultSet.getObject(i));
}
datas.add(rowMap);
}
System.out.println("成功查詢到了" + datas.size() + "行資料");
for (int i = 0; i < datas.size(); i++) {
Map<String, Object> map = datas.get(i);
System.out.println("第" + (i + 1) + "行：" + map);
}
return datas;
}
/**
* Build an SQL query string from the given clauses.
*
* @param distinct true if you want each row to be unique, false otherwise.
* @param tables The table names to compile the query against.
* @param columns A list of which columns to return. Passing null will
* return all columns, which is discouraged to prevent reading
* data from storage that isn't going to be used.
* @param where A filter declaring which rows to return, formatted as an SQL
* WHERE clause (excluding the WHERE itself). Passing null will
* return all rows for the given URL.
* @param groupBy A filter declaring how to group rows, formatted as an SQL
* GROUP BY clause (excluding the GROUP BY itself). Passing null
* will cause the rows to not be grouped.
* @param having A filter declare which row groups to include in the cursor,
* if row grouping is being used, formatted as an SQL HAVING
* clause (excluding the HAVING itself). Passing null will cause
* all row groups to be included, and is required when row
* grouping is not being used.
* @param orderBy How to order the rows, formatted as an SQL ORDER BY clause
* (excluding the ORDER BY itself). Passing null will use the
* default sort order, which may be unordered.
* @param limit Limits the number of rows returned by the query,
* formatted as LIMIT clause. Passing null denotes no LIMIT clause.
* @return the SQL query string
*/
private static String buildQueryString(
boolean distinct, String tables, String[] columns, String where,
String groupBy, String having, String orderBy, String limit) {
if (isEmpty(groupBy) && !isEmpty(having)) {
throw new IllegalArgumentException(
"HAVING clauses are only permitted when using a groupBy clause");
}
if (!isEmpty(limit) && !sLimitPattern.matcher(limit).matches()) {
throw new IllegalArgumentException("invalid LIMIT clauses:" + limit);
}
StringBuilder query = new StringBuilder(120);
query.append("SELECT ");
if (distinct) {
query.append("DISTINCT ");
}
if (columns != null && columns.length != 0) {
appendColumns(query, columns);
} else {
query.append(" * ");
}
query.append("FROM ");
query.append(tables);
appendClause(query, " WHERE ", where);
appendClause(query, " GROUP BY ", groupBy);
appendClause(query, " HAVING ", having);
appendClause(query, " ORDER BY ", orderBy);
appendClause(query, " LIMIT ", limit);
return query.toString();
}
/**
* Add the names that are non-null in columns to s, separating
* them with commas.
*/
private static void appendColumns(StringBuilder s, String[] columns) {
int n = columns.length;
for (int i = 0; i < n; i++) {
String column = columns[i];
if (column != null) {
if (i > 0) {
s.append(", ");
}
s.append(column);
}
}
s.append(' ');
}
/**
* addClause
*
* @param s the add StringBuilder
* @param name clauseName
* @param clause clauseSelection
*/
private static void appendClause(StringBuilder s, String name, String clause) {
if (!isEmpty(clause)) {
s.append(name);
s.append(clause);
}
}
/**
* Returns true if the string is null or 0-length.
*
* @param str the string to be examined
* @return true if str is null or zero length
*/
private static boolean isEmpty(@Nullable CharSequence str) {
if (str == null || str.length() == 0)
return true;
else
return false;
}
/**
* the pattern of limit
*/
private static final Pattern sLimitPattern =
Pattern.compile("\\s*\\d+\\s*(,\\s*\\d+\\s*)?");
/**
* After the execution of the complete SQL statement, not necessarily the actual implementation of the SQL statement
*
* @param sql SQL statement
* @param bindArgs Binding parameters
* @return Replace? SQL statement executed after the
*/
private static String getExecSQL(String sql, Object[] bindArgs) {
StringBuilder sb = new StringBuilder(sql);
if (bindArgs != null && bindArgs.length > 0) {
int index = 0;
for (int i = 0; i < bindArgs.length; i++) {
index = sb.indexOf("?", index);
sb.replace(index, index + 1, String.valueOf(bindArgs[i]));
}
}
return sb.toString();
}
}複製程式碼九.用法
- 測試程式碼
import util.DBUtil;
import java.sql.SQLException;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Created by yuandl on 2016-12-16.
*/
public class DBTest {
public static void main(String[] args) {
System.out.println("資料庫的原資料");
testQuery3();
testInsert();
System.out.println("執行插入後的資料");
testQuery3();
testUpdate();
System.out.println("執行修改後的資料");
testQuery3();
testDelete();
System.out.println("執行刪除後的資料");
testQuery3();
System.out.println("帶條件的查詢1");
testQuery2();
System.out.println("帶條件的查詢2");
testQuery1();
}
/**
* 測試插入
*/
private static void testInsert() {
Map<String, Object> map = new HashMap<>();
map.put("emp_id", 1013);
map.put("name", "JDBCUtil測試");
map.put("job", "developer");
map.put("salary", 10000);
map.put("hire_date", new java.sql.Date(System.currentTimeMillis()));
try {
int count = DBUtil.insert("emp_test", map);
} catch (SQLException e) {
e.printStackTrace();
}
}
/**
* 測試更新
*/
private static void testUpdate() {
Map<String, Object> map = new HashMap<>();
map.put("name", "測試更新");
Map<String, Object> whereMap = new HashMap<>();
whereMap.put("emp_id", "1013");
try {
int count = DBUtil.update("emp_test", map, whereMap);
} catch (SQLException e) {
e.printStackTrace();
}
}
/**
* 測試刪除
*/
private static void testDelete() {
Map<String, Object> whereMap = new HashMap<>();
whereMap.put("emp_id", 1013);
whereMap.put("job", "developer");
try {
int count = DBUtil.delete("emp_test", whereMap);
} catch (SQLException e) {
e.printStackTrace();
}
}
/**
* 查詢方式一
*/
public static void testQuery1() {
Map<String,Object> whereMap=new HashMap<>();
whereMap.put("salary","10000");
try {
DBUtil.query("emp_test",whereMap);
} catch (SQLException e) {
e.printStackTrace();
}
}
/**
* 查詢方式二
*/
public static void testQuery2() {
String where = "job = ? AND salary = ? ";
String[] whereArgs = new String[]{"clerk", "3000"};
try {
List<Map<String, Object>> list = DBUtil.query("emp_test", where, whereArgs);
} catch (SQLException e) {
e.printStackTrace();
}
}
/**
* 查詢方式三
*/
public static void testQuery3() {
try {
List<Map<String, Object>> list = DBUtil.query("emp_test", false, null, null, null, null, null, null, null);
} catch (SQLException e) {
e.printStackTrace();
}
}
}複製程式碼- 列印結果
資料庫的原資料
SELECT * FROM emp_test
成功查詢到了14行資料
第1行：{DEPT_TEST_ID=10, EMP_ID=1001, SALARY=10000, HIRE_DATE=2010-01-12, BONUS=2000, MANAGER=1005, JOB=Manager, NAME=張無忌}
第2行：{DEPT_TEST_ID=10, EMP_ID=1002, SALARY=8000, HIRE_DATE=2011-01-12, BONUS=1000, MANAGER=1001, JOB=Analyst, NAME=劉蒼松}
第3行：{DEPT_TEST_ID=10, EMP_ID=1003, SALARY=9000, HIRE_DATE=2010-02-11, BONUS=1000, MANAGER=1001, JOB=Analyst, NAME=李翊}
第4行：{DEPT_TEST_ID=10, EMP_ID=1004, SALARY=5000, HIRE_DATE=2010-02-11, BONUS=null, MANAGER=1001, JOB=Programmer, NAME=郭芙蓉}
第5行：{DEPT_TEST_ID=20, EMP_ID=1005, SALARY=15000, HIRE_DATE=2008-02-15, BONUS=null, MANAGER=null, JOB=President, NAME=張三丰}
第6行：{DEPT_TEST_ID=20, EMP_ID=1006, SALARY=5000, HIRE_DATE=2009-02-01, BONUS=400, MANAGER=1005, JOB=Manager, NAME=燕小六}
第7行：{DEPT_TEST_ID=20, EMP_ID=1007, SALARY=3000, HIRE_DATE=2009-02-01, BONUS=500, MANAGER=1006, JOB=clerk, NAME=陸無雙}
第8行：{DEPT_TEST_ID=30, EMP_ID=1008, SALARY=5000, HIRE_DATE=2009-05-01, BONUS=500, MANAGER=1005, JOB=Manager, NAME=黃蓉}
第9行：{DEPT_TEST_ID=30, EMP_ID=1009, SALARY=4000, HIRE_DATE=2009-02-20, BONUS=null, MANAGER=1008, JOB=salesman, NAME=韋小寶}
第10行：{DEPT_TEST_ID=30, EMP_ID=1010, SALARY=4500, HIRE_DATE=2009-05-10, BONUS=500, MANAGER=1008, JOB=salesman, NAME=郭靖}
第11行：{DEPT_TEST_ID=null, EMP_ID=1011, SALARY=null, HIRE_DATE=null, BONUS=null, MANAGER=null, JOB=null, NAME=於澤成}
第12行：{DEPT_TEST_ID=null, EMP_ID=1012, SALARY=null, HIRE_DATE=2011-08-10, BONUS=null, MANAGER=null, JOB=null, NAME=amy}
第13行：{DEPT_TEST_ID=null, EMP_ID=1014, SALARY=8000, HIRE_DATE=null, BONUS=null, MANAGER=null, JOB=null, NAME=張無忌}
第14行：{DEPT_TEST_ID=20, EMP_ID=1015, SALARY=null, HIRE_DATE=null, BONUS=null, MANAGER=null, JOB=null, NAME=劉蒼松}
INSERT INTO emp_test (name,hire_date,job,salary,emp_id ) VALUES (JDBCUtil測試,2016-12-17,developer,10000,1013 )
成功新增了1行
執行插入後的資料
SELECT * FROM emp_test
成功查詢到了15行資料
第1行：{DEPT_TEST_ID=10, EMP_ID=1001, SALARY=10000, HIRE_DATE=2010-01-12, BONUS=2000, MANAGER=1005, JOB=Manager, NAME=張無忌}
第2行：{DEPT_TEST_ID=10, EMP_ID=1002, SALARY=8000, HIRE_DATE=2011-01-12, BONUS=1000, MANAGER=1001, JOB=Analyst, NAME=劉蒼松}
第3行：{DEPT_TEST_ID=10, EMP_ID=1003, SALARY=9000, HIRE_DATE=2010-02-11, BONUS=1000, MANAGER=1001, JOB=Analyst, NAME=李翊}
第4行：{DEPT_TEST_ID=10, EMP_ID=1004, SALARY=5000, HIRE_DATE=2010-02-11, BONUS=null, MANAGER=1001, JOB=Programmer, NAME=郭芙蓉}
第5行：{DEPT_TEST_ID=20, EMP_ID=1005, SALARY=15000, HIRE_DATE=2008-02-15, BONUS=null, MANAGER=null, JOB=President, NAME=張三丰}
第6行：{DEPT_TEST_ID=20, EMP_ID=1006, SALARY=5000, HIRE_DATE=2009-02-01, BONUS=400, MANAGER=1005, JOB=Manager, NAME=燕小六}
第7行：{DEPT_TEST_ID=20, EMP_ID=1007, SALARY=3000, HIRE_DATE=2009-02-01, BONUS=500, MANAGER=1006, JOB=clerk, NAME=陸無雙}
第8行：{DEPT_TEST_ID=30, EMP_ID=1008, SALARY=5000, HIRE_DATE=2009-05-01, BONUS=500, MANAGER=1005, JOB=Manager, NAME=黃蓉}
第9行：{DEPT_TEST_ID=30, EMP_ID=1009, SALARY=4000, HIRE_DATE=2009-02-20, BONUS=null, MANAGER=1008, JOB=salesman, NAME=韋小寶}
第10行：{DEPT_TEST_ID=30, EMP_ID=1010, SALARY=4500, HIRE_DATE=2009-05-10, BONUS=500, MANAGER=1008, JOB=salesman, NAME=郭靖}
第11行：{DEPT_TEST_ID=null, EMP_ID=1011, SALARY=null, HIRE_DATE=null, BONUS=null, MANAGER=null, JOB=null, NAME=於澤成}
第12行：{DEPT_TEST_ID=null, EMP_ID=1012, SALARY=null, HIRE_DATE=2011-08-10, BONUS=null, MANAGER=null, JOB=null, NAME=amy}
第13行：{DEPT_TEST_ID=null, EMP_ID=1014, SALARY=8000, HIRE_DATE=null, BONUS=null, MANAGER=null, JOB=null, NAME=張無忌}
第14行：{DEPT_TEST_ID=20, EMP_ID=1015, SALARY=null, HIRE_DATE=null, BONUS=null, MANAGER=null, JOB=null, NAME=劉蒼松}
第15行：{DEPT_TEST_ID=null, EMP_ID=1013, SALARY=10000, HIRE_DATE=2016-12-17, BONUS=null, MANAGER=null, JOB=developer, NAME=JDBCUtil測試}
UPDATE emp_test SET name = 測試更新 WHERE emp_id = 1013
成功修改了1行
執行修改後的資料
SELECT * FROM emp_test
成功查詢到了15行資料
第1行：{DEPT_TEST_ID=10, EMP_ID=1001, SALARY=10000, HIRE_DATE=2010-01-12, BONUS=2000, MANAGER=1005, JOB=Manager, NAME=張無忌}
第2行：{DEPT_TEST_ID=10, EMP_ID=1002, SALARY=8000, HIRE_DATE=2011-01-12, BONUS=1000, MANAGER=1001, JOB=Analyst, NAME=劉蒼松}
第3行：{DEPT_TEST_ID=10, EMP_ID=1003, SALARY=9000, HIRE_DATE=2010-02-11, BONUS=1000, MANAGER=1001, JOB=Analyst, NAME=李翊}
第4行：{DEPT_TEST_ID=10, EMP_ID=1004, SALARY=5000, HIRE_DATE=2010-02-11, BONUS=null, MANAGER=1001, JOB=Programmer, NAME=郭芙蓉}
第5行：{DEPT_TEST_ID=20, EMP_ID=1005, SALARY=15000, HIRE_DATE=2008-02-15, BONUS=null, MANAGER=null, JOB=President, NAME=張三丰}
第6行：{DEPT_TEST_ID=20, EMP_ID=1006, SALARY=5000, HIRE_DATE=2009-02-01, BONUS=400, MANAGER=1005, JOB=Manager, NAME=燕小六}
第7行：{DEPT_TEST_ID=20, EMP_ID=1007, SALARY=3000, HIRE_DATE=2009-02-01, BONUS=500, MANAGER=1006, JOB=clerk, NAME=陸無雙}
第8行：{DEPT_TEST_ID=30, EMP_ID=1008, SALARY=5000, HIRE_DATE=2009-05-01, BONUS=500, MANAGER=1005, JOB=Manager, NAME=黃蓉}
第9行：{DEPT_TEST_ID=30, EMP_ID=1009, SALARY=4000, HIRE_DATE=2009-02-20, BONUS=null, MANAGER=1008, JOB=salesman, NAME=韋小寶}
第10行：{DEPT_TEST_ID=30, EMP_ID=1010, SALARY=4500, HIRE_DATE=2009-05-10, BONUS=500, MANAGER=1008, JOB=salesman, NAME=郭靖}
第11行：{DEPT_TEST_ID=null, EMP_ID=1011, SALARY=null, HIRE_DATE=null, BONUS=null, MANAGER=null, JOB=null, NAME=於澤成}
第12行：{DEPT_TEST_ID=null, EMP_ID=1012, SALARY=null, HIRE_DATE=2011-08-10, BONUS=null, MANAGER=null, JOB=null, NAME=amy}
第13行：{DEPT_TEST_ID=null, EMP_ID=1014, SALARY=8000, HIRE_DATE=null, BONUS=null, MANAGER=null, JOB=null, NAME=張無忌}
第14行：{DEPT_TEST_ID=20, EMP_ID=1015, SALARY=null, HIRE_DATE=null, BONUS=null, MANAGER=null, JOB=null, NAME=劉蒼松}
第15行：{DEPT_TEST_ID=null, EMP_ID=1013, SALARY=10000, HIRE_DATE=2016-12-17, BONUS=null, MANAGER=null, JOB=developer, NAME=測試更新}
DELETE FROM emp_test WHERE job = developer AND emp_id = 1013
成功刪除了1行
執行刪除後的資料
SELECT * FROM emp_test
成功查詢到了14行資料
第1行：{DEPT_TEST_ID=10, EMP_ID=1001, SALARY=10000, HIRE_DATE=2010-01-12, BONUS=2000, MANAGER=1005, JOB=Manager, NAME=張無忌}
第2行：{DEPT_TEST_ID=10, EMP_ID=1002, SALARY=8000, HIRE_DATE=2011-01-12, BONUS=1000, MANAGER=1001, JOB=Analyst, NAME=劉蒼松}
第3行：{DEPT_TEST_ID=10, EMP_ID=1003, SALARY=9000, HIRE_DATE=2010-02-11, BONUS=1000, MANAGER=1001, JOB=Analyst, NAME=李翊}
第4行：{DEPT_TEST_ID=10, EMP_ID=1004, SALARY=5000, HIRE_DATE=2010-02-11, BONUS=null, MANAGER=1001, JOB=Programmer, NAME=郭芙蓉}
第5行：{DEPT_TEST_ID=20, EMP_ID=1005, SALARY=15000, HIRE_DATE=2008-02-15, BONUS=null, MANAGER=null, JOB=President, NAME=張三丰}
第6行：{DEPT_TEST_ID=20, EMP_ID=1006, SALARY=5000, HIRE_DATE=2009-02-01, BONUS=400, MANAGER=1005, JOB=Manager, NAME=燕小六}
第7行：{DEPT_TEST_ID=20, EMP_ID=1007, SALARY=3000, HIRE_DATE=2009-02-01, BONUS=500, MANAGER=1006, JOB=clerk, NAME=陸無雙}
第8行：{DEPT_TEST_ID=30, EMP_ID=1008, SALARY=5000, HIRE_DATE=2009-05-01, BONUS=500, MANAGER=1005, JOB=Manager, NAME=黃蓉}
第9行：{DEPT_TEST_ID=30, EMP_ID=1009, SALARY=4000, HIRE_DATE=2009-02-20, BONUS=null, MANAGER=1008, JOB=salesman, NAME=韋小寶}
第10行：{DEPT_TEST_ID=30, EMP_ID=1010, SALARY=4500, HIRE_DATE=2009-05-10, BONUS=500, MANAGER=1008, JOB=salesman, NAME=郭靖}
第11行：{DEPT_TEST_ID=null, EMP_ID=1011, SALARY=null, HIRE_DATE=null, BONUS=null, MANAGER=null, JOB=null, NAME=於澤成}
第12行：{DEPT_TEST_ID=null, EMP_ID=1012, SALARY=null, HIRE_DATE=2011-08-10, BONUS=null, MANAGER=null, JOB=null, NAME=amy}
第13行：{DEPT_TEST_ID=null, EMP_ID=1014, SALARY=8000, HIRE_DATE=null, BONUS=null, MANAGER=null, JOB=null, NAME=張無忌}
第14行：{DEPT_TEST_ID=20, EMP_ID=1015, SALARY=null, HIRE_DATE=null, BONUS=null, MANAGER=null, JOB=null, NAME=劉蒼松}
帶條件的查詢1
SELECT * FROM emp_test WHERE job = clerk AND salary = 3000
成功查詢到了1行資料
第1行：{DEPT_TEST_ID=20, EMP_ID=1007, SALARY=3000, HIRE_DATE=2009-02-01, BONUS=500, MANAGER=1006, JOB=clerk, NAME=陸無雙}
帶條件的查詢2
SELECT * FROM emp_test WHERE salary = 10000
成功查詢到了1行資料
第1行：{DEPT_TEST_ID=10, EMP_ID=1001, SALARY=10000, HIRE_DATE=2010-01-12, BONUS=2000, MANAGER=1005, JOB=Manager, NAME=張無忌}複製程式碼