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java 常用文件管理

程序员文章站 2022-03-02 17:17:01
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package file;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.RandomAccessFile;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;

/**
* File Operation Class
* 
* @author liangyongbiao
*
*/
public class FileOperate {

/**
* Read Form File
* @throws IOException 
*/
public static List<String> ReadFromFile(String strfile) throws IOException {

CheckFileExit(strfile);
File file = new File(strfile);
List<String> list=new ArrayList<String>();
try {
InputStreamReader read = new InputStreamReader(new FileInputStream(
file), "GBK");
BufferedReader bufferedReader = new BufferedReader(read);
String lineTxt = null;
while ((lineTxt = bufferedReader.readLine()) != null) {
list.add(lineTxt);
}
read.close();
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

return list;

}

public static void main(String[] args) throws IOException {

WriteToFileWithOneLine("D:/file/fileoper.txt", "附近萨芬的克里斯");
// System.out.println(CheckFileNotNull("D:/file/fileoper.txt"));

}

/**
* Write To File
* @throws IOException 
*/
public static void WriteToFile(String strfile,String str) throws IOException {

File file=new File(strfile);
CheckFileExit(strfile);
RandomAccessFile randomAccessFile=null;
try{
randomAccessFile=new RandomAccessFile(file, "rw");
long fileLength=randomAccessFile.length();
randomAccessFile.seek(fileLength);
randomAccessFile.writeBytes(str);
//也可以使用下面的方式追加
// FileWriter writer = new FileWriter(file, true);
//     writer.write(str);
//     writer.close();
}catch(IOException e){
e.printStackTrace();
}
finally{
if(randomAccessFile!=null){
try{
randomAccessFile.close();
}catch(IOException e){
e.printStackTrace();
}
}
}


}

/**
* Check File is exit or not
*/
public static void CheckFileExit(String strfile) {
File file = new File(strfile);
if (!file.exists()) {
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
}
}

/**
* Clean File
*/
public static void CleanFile(String strfile) {

CheckFileExit(strfile);
try {
FileWriter fileWriter = new FileWriter(strfile);
fileWriter.write("");
fileWriter.flush();
fileWriter.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

/**
* @author liangyongbiao
* Copy A File Content
*/
public File CopyFileToFile(File sourceFile, File ReturnFile) {
return ReturnFile;
}

/**
* @author liangyongbiao
* Append To File end
*/
public File AppendToFileEnd(String strfile) {

CheckFileExit(strfile);
File file = new File(strfile);
return file;
}

/**
* Check File Content is null or not
* @throws IOException 
*/
@SuppressWarnings("resource")
public static Boolean CheckFileNotNull(String strfile) throws IOException {

Boolean flag = false;
File file=new File(strfile);
CheckFileExit(strfile);
FileInputStream fileInputStream;
try {
fileInputStream = new FileInputStream(file);
        int size=fileInputStream.available();
        if(size==0){
           System.out.println("文件为空!!");
        }else{
           flag=true;
        }
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

return flag;

}

/**
* Radrom Write To File
*/
public File randomWriteToFile(String strfile, String str) {

File file = new File(strfile);
return file;
}


/**
* One Line One Read
*/
public static File WriteToFileWithOneLine(String strfile,String str){
File file=new File(strfile);
CheckFileExit(strfile);
FileWriter writer;
try {
writer = new FileWriter(file, true);
str=str+"\n";
writer.write(str);
writer.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
  
return file;
}

}
 

 

相关标签: java 文件操作