java如何对文件追加写入

Question

public static void main(String[] args)throws Exception{
try{
BufferedReader br = new BufferedReader(new FileReader("E:\\a.txt"));
String s;

while((s=br.readLine())!=null)
{
File f = new File("E：\\"+File.separator+"b.txt");
OutputStream out = new FileOutputStream(f,true);
out.write(s.getBytes());
out.close();

}
System.out.println("成功存入~！");

}catch(Exception e){
System.out.println("error:"+e);
}
}

}
这是我的代码，追加写入就乱码了...

Answer 1

java文件追加内容的三种方法：
方法一：
public static void writeToTxtByRandomAccessFile(File file, String str){
RandomAccessFile randomAccessFile = null;
try {
randomAccessFile = new RandomAccessFile(file,"rw");
long len = randomAccessFile.length();
randomAccessFile.seek(len);
randomAccessFile.writeBytes(new String(str.getBytes(),"iso8859-1")+"\r\n");
} catch (FileNotFoundException e) {
e.printStackTrace();
}catch (IOException e) {
e.printStackTrace();
}finally{
try {
randomAccessFile.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
方法二：
public static void writeToTxtByFileWriter(File file, String content){
BufferedWriter bw = null;
try {
FileWriter fw = new FileWriter(file, true);
bw = new BufferedWriter(fw);
bw.write(content);
} catch (IOException e) {
e.printStackTrace();
}finally{
try {
bw.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
方法三：
public static void writeToTxtByOutputStream(File file, String content){
BufferedOutputStream bufferedOutputStream = null;
try {
bufferedOutputStream = new BufferedOutputStream(new FileOutputStream(file, true));
bufferedOutputStream.write(content.getBytes());
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch(IOException e ){
e.printStackTrace();
}finally{
try {
bufferedOutputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}

Answer 2

带编码处理
public static void main(String args[]) {
try {
InputStreamReader is = new InputStreamReader(new FileInputStream(
"E:\\a.txt"), "gbk");
BufferedReader br = new BufferedReader(is);
File f = new File("E:\\b.txt");
String s;
while ((s = br.readLine()) != null) {
BufferedWriter bw = new BufferedWriter(new FileWriter(f, true));
bw.write(s);
bw.newLine();
bw.close();
}
System.out.println("成功存入~！");

} catch (Exception e) {
System.out.println("error:" + e);
}
}本回答被提问者采纳

Answer 3

读取文件内容使用的这些类：BufferedReader br = new BufferedReader(new FileReader("E:\\a.txt"));
然后写入的时候用的这个：OutputStream out = new FileOutputStream(f,true);
一个是字符流，一个是字节流。你试试把FileOutputStream改为FileWriter试试，或者怎么处理下用上BufferedWriter 和 FileWriter

Answer 4

这个不就是可以吗？？追问

不行啊，一追加就乱码了....

Answer 5

编码问题吧。