Java读取和写入文本文件内容

1、Java 写入文本文件源码

 

import java.io.BufferedWriter;



import java.io.File;



import java.io.FileOutputStream;



import java.io.IOException;



import java.io.OutputStreamWriter; 



public class TxtWriter { 



    public static void appendToFile(String content, File file) throws IOException {

        TxtWriter.appendToFile(content, file, System.getProperty("file.encoding"));

    }

    public static void appendToFile(String content, File file, String encoding) throws IOException {

        BufferedWriter writer = null;

        try {

            writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file, true), encoding));

            writer.write(content);

        } finally {

         if (writer != null)



                writer.close();



        }

    } 

 



    public static void saveToFile(String content, File file) throws IOException {



        TxtWriter.saveToFile(content, file, System.getProperty("file.encoding"));

    } 

 



    public static void saveToFile(String content, File file, String encoding) throws IOException {



        BufferedWriter writer = null;



        try {



            writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file, false), encoding));



            writer.write(content);



        } finally {



            if (writer != null)



                writer.close();



        }

    }

}

　　2、Java 读取文本文件源码

import java.io.BufferedReader;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStreamReader; 

 



public class TxtReader { 

 

    /**

     * 从文件中读取文本内容, 读取时使用平台默认编码解码文件中的字节序列

     * @param file 目标文件

     * @return

     * @throws IOException

     */

    public static String loadStringFromFile(File file) throws IOException {

        return TxtReader.loadStringFromFile(file, System.getProperty("file.encoding"));

    } 

 



    /**

     * 从文件中读取文本内容

    * @param file 目标文件

     * @param encoding 目标文件的文本编码格式

     * @return

     * @throws IOException

     */

    public static String loadStringFromFile(File file, String encoding) throws IOException {

        BufferedReader reader = null;

        try {

            reader = new BufferedReader(new InputStreamReader(new FileInputStream(file), encoding));

            StringBuilder builder = new StringBuilder();

            char[] chars = new char[4096];



            int length = 0;



            while (0 < (length = reader.read(chars))) {



                builder.append(chars, 0, length);



            }



            return builder.toString();



        } finally {



            try {



                if (reader != null) reader.close();



            } catch (IOException e) {



                throw new RuntimeException(e);



            }



        }



    } 

}

　　转载自：http://www.appfen.com/2012/java-input-output-txt.html