import java.io.BufferedWriter;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.RandomAccessFile;
//如果文件存在，則追加內(nèi)容；如果文件不存在，則創(chuàng)建文件，追加內(nèi)容的三種方法
public class AppendContentToFile {
@SuppressWarnings("static-access")
public static void main(String[] args) {
AppendContentToFile a = new AppendContentToFile();
a.method1();
a.method2("E:\\dd.txt", "222222222222222");
a.method3("E:\\dd.txt", "33333333333");
}

public void method1() {
FileWriter fw = null;
try {
//如果文件存在，則追加內(nèi)容；如果文件不存在，則創(chuàng)建文件
File f=new File("E:\\dd.txt");
fw = new FileWriter(f, true);
} catch (IOException e) {
e.printStackTrace();
}
PrintWriter pw = new PrintWriter(fw);
pw.println("追加內(nèi)容");
pw.flush();
try {
fw.flush();
pw.close();
fw.close();
} catch (IOException e) {
e.printStackTrace();
}
}

public static void method2(String file, String conent) {
BufferedWriter out = null;
try {
out = new BufferedWriter(new OutputStreamWriter(
new FileOutputStream(file, true)));
out.write(conent+"\r\n");
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
out.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}

public static void method3(String fileName, String content) {
try {
// 打開(kāi)一個(gè)隨機(jī)訪問(wèn)文件流，按讀寫(xiě)方式
RandomAccessFile randomFile = new RandomAccessFile(fileName, "rw");
// 文件長(zhǎng)度，字節(jié)數(shù)
long fileLength = randomFile.length();
// 將寫(xiě)文件指針移到文件尾。
randomFile.seek(fileLength);
randomFile.writeBytes(content+"\r\n");
randomFile.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}