java工作常用簡單工具
檔案複製
當專案部署於伺服器上時，檔案的複製就沒有那麼方便了
public class FileTransfer {
public static void main(String[] args) throws IOException {
String oldFilePath = "C:\\Users\\admin\\Desktop\\asd.txt";
String newFilePath = "C:\\Users\\admin\\Desktop\\zzz.jpg";
fileTransfer(oldFilePath, newFilePath);
}
public static void fileTransfer(String oldFilePath, String newFilePath) {
try {
File oldFile = new File(oldFilePath);
if(!oldFile.exists()) {
return;
}
File newFile = new File(newFilePath);
File parentFile = newFile.getParentFile();
if(!parentFile.exists()) {
parentFile.mkdirs();
}
if(!newFile.exists()) {
newFile.createNewFile();
}
InputStream in = new FileInputStream(oldFile);
OutputStream out = new FileOutputStream(newFile);
byte[] buffer = new byte[1024];
int len;
while ((len = in.read(buffer)) > 0) {
out.write(buffer, 0, len);
}
out.close();
in.close();
System.out.println(oldFilePath + "檔案複製成功");
}catch (Exception e) {
System.out.println(oldFilePath + "檔案複製失敗");
e.printStackTrace();
}
}
}
迴圈寫入檔案
有時需要將資料從資料庫中讀出，進行字串拼接生成sql，寫入指定檔案
public class CycleWrite {
public static void writeContent(BufferedWriter bw) {
}
public static void main(String[] args) {
String txtFilePath = "c:\\user\\admin\\desktop\\xxx.txt";
cycleWrite(txtFilePath);
}
public static void cycleWrite(String txtFilePath) {
BufferedWriter bw = null;
FileWriter fileWriter = null;
try {
File file =new File(txtFilePath);
if(!file.exists()){
file.createNewFile();
}
fileWriter = new FileWriter(file.getAbsoluteFile());
bw = new BufferedWriter(fileWriter);
writeContent(bw);
bw.close();
fileWriter.close();
}catch (Exception e) {
e.printStackTrace();
}
System.out.println("寫入完成");
}
}
Txt檔案讀取
從txt檔案中讀取 拼接sql寫入指定檔案
public class ReadText {
public static void main(String[] args) {
String txtFilePath = "C:\\Users\\admin\\Desktop\\asd.txt";
String targetFilePath = "C:\\Users\\admin\\Desktop\\xxx.txt";
readTxt(txtFilePath, targetFilePath);
}
public static void operationTxtContent(BufferedWriter bw, String lineTxt, int index, Map tempMap) throws IOException {
}
public static void readTxt(String txtFilePath, String targetFilePath) {
InputStream inputStream = null;
InputStreamReader read = null;
BufferedReader bufferedReader = null;
BufferedWriter bw = null;
FileWriter fileWriter = null;
try {
String encoding="UTF-8";
File file = new File(txtFilePath);
if(file.isFile() && file.exists()) {
File outFile =new File(targetFilePath);
if(!outFile.exists()){
outFile.createNewFile();
}
inputStream = new FileInputStream(file);
read = new InputStreamReader(inputStream,encoding);
bufferedReader = new BufferedReader(read);
fileWriter = new FileWriter(outFile.getAbsoluteFile());
bw = new BufferedWriter(fileWriter);
String lineTxt = null;
Map tempMap = new HashMap();
Connection content = SqlConnect.getSqlLiteContent();
tempMap.put("connection", content);
int i = 0;
while((lineTxt = bufferedReader.readLine()) != null){
try {
operationTxtContent(bw, lineTxt, i, tempMap);
i++;
} catch(Exception e) {
e.printStackTrace();
}
}
}else {
System.out.println("檔案不存在");
}
bw.close();
fileWriter.close();
bufferedReader.close();
read.close();
inputStream.close();
}catch(Exception e) {
e.printStackTrace();
}
System.out.println("讀取完成");
}
}
xlsx表格讀取
工作中難免需要操作xlsx 讀出然後進行sql拼接 寫入檔案
需要POI的依賴
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>4.0.1</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>4.0.1</version>
</dependency>
public class ReadXlsx {
public static void main(String[] args) {
String xlsxFilePath = "C:\\Users\\admin\\Desktop\\xxx.xlsx";
String targetFilePath = "C:\\Users\\admin\\Desktop\\test_appendfile_asd.txt";
readXlsx(xlsxFilePath, targetFilePath);
}
public static void operationXlsxContent(BufferedWriter bw, Row row, int index) {
}
public static void readXlsx(String xlsxFilePath, String targetFilePath) {
BufferedWriter bw = null;
FileWriter fileWriter = null;
try {
XSSFWorkbook workbook = new XSSFWorkbook(new FileInputStream(new File(xlsxFilePath)));
XSSFSheet sheetAt = workbook.getSheetAt(0);
File file =new File(targetFilePath);
if(!file.exists()){
file.createNewFile();
}
fileWriter = new FileWriter(file.getAbsoluteFile());
bw = new BufferedWriter(fileWriter);
int i = 0;
for(Row row : sheetAt) {
try {
operationXlsxContent(bw, row, i);
i++;
}catch(Exception e) {
e.printStackTrace();
}
}
bw.close();
fileWriter.close();
}catch (Exception e) {
e.printStackTrace();
}
System.out.println("讀取完成");
}
}
xlsx寫入
當然這裡的寫入值得是迴圈寫入 複雜性的寫入 還是建議去直接手動去寫
public class WriteXlsx {
public static void main(String[] args) {
String filePath = "C:\\Users\\admin\\Desktop\\test_appendfile_asd.xls";
String sheetName = "月報表";
List titleList = new ArrayList<String>();
titleList.add("姓名");
titleList.add("性別");
List keyList = new ArrayList<String>();
keyList.add("name");
keyList.add("sex");
List content = new ArrayList<Map>();
Map map1 = new HashMap();
map1.put("name", "張三");
map1.put("sex", "女");
content.add(map1);
Map map2 = new HashMap();
map2.put("name", "李四");
map2.put("sex", "男");
content.add(map2);
writeXlsxList(filePath, sheetName, titleList, keyList, content);
}
public static void writeXlsxList(String filePath, String sheetName, List<String> titleList, List<String> keyList, List<Map> content) {
writeXlsxMain(filePath, sheetName, "list", titleList, keyList, content);
}
private static void writeXlsxMain(String filePath, String sheetName, String type, List<String> titleList,List<String> keyList, List<Map> content) {
FileOutputStream fOut = null;
try {
HSSFWorkbook workbook = new HSSFWorkbook();
HSSFSheet sheet = workbook.createSheet(sheetName);
xlsxContent(sheet, titleList, keyList, content);
fOut = new FileOutputStream(filePath);
workbook.write(fOut);
fOut.flush();
fOut.close();
}catch(Exception e) {
e.printStackTrace();
}
System.out.println("完畢");
}
private static void xlsxContent(HSSFSheet sheet, List<String> titleList, List<String> keyList, List<Map> content) {
if(titleList.size() != keyList.size()) {
System.out.println("標題的長度與內容長度不一致");
return;
}
int rowCount = 0;
HSSFRow row = sheet.createRow(rowCount);
rowCount++;
for(int i = 0;i < titleList.size();i++) {
HSSFCell cell = row.createCell(i);
cell.setCellValue(titleList.get(i));
}
for(Map contentMap : content) {
row = sheet.createRow(rowCount);
int i = 0;
for(String key : keyList) {
HSSFCell cell = row.createCell(i);
cell.setCellValue(MapUtils.getString(contentMap, key));
i++;
}
rowCount++;
}
}
}