package com.syj.util;
//转贴 http://blog.youkuaiyun.com/sunyujia/archive/2008/06/15/2551297.aspx
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.StringReader;
import java.util.Arrays;
/**
* <p>
* Title:IO工具类
* </p>
*
* <p>
* Description:常用的IO操作封装
* </p>
*
* <p>
* Copyright: 转载请注明出处http://blog.youkuaiyun.com/sunyujia/
* </p>
*
* @author 孙钰佳
* @main sunyujia@yahoo.cn
* @date Jun 15, 2008 4:37:58 PM
*/
public class IOUtil {
/**
* 缓冲区大小 1MB
*/
private static final int BUFFER_SIZE = 1024 * 1024;
/**
*
* Description: 将输入流输出到输出流
*
* @param in
* 输入流
* @param out
* 输出流
* @param bufferSize
* 缓冲区大小
* @throws IOException
* @mail sunyujia@yahoo.cn
* @since：Jun 15, 2008 5:57:24 PM
*/
public static void in2OutStream(InputStream in, OutputStream out, int bufferSize) throws IOException {
byte[] buffer = new byte[bufferSize];// 缓冲区
for (int bytesRead = 0; (bytesRead = in.read(buffer)) != -1;) {
out.write(buffer, 0, bytesRead);
Arrays.fill(buffer, (byte) 0);
}
}
/**
*
* Description: 读取文件返回字节数组流
*
* @param file
* 文件
* @return 字节数组流
* @mail sunyujia@yahoo.cn
* @since：Jun 15, 2008 4:52:41 PM
*/
public static ByteArrayOutputStream readFileToByteStream(File file) throws IOException {
FileInputStream fis = null;
ByteArrayOutputStream bos = null;
try {
fis = new FileInputStream(file);
bos = new ByteArrayOutputStream();
in2OutStream(fis, bos, BUFFER_SIZE);
} finally {
if (fis != null)
fis.close();
}
return bos;
}
/**
*
* Description:读取文件返回字节数组
*
* @param file
* 文件
* @return 字节数组
* @throws IOException
* @mail sunyujia@yahoo.cn
* @since：Jun 15, 2008 5:38:50 PM
*/
public static byte[] readFileToByteArray(File file) throws IOException {
ByteArrayOutputStream bos = null;
try {
bos = readFileToByteStream(file);
} finally {
if (bos != null)
bos.close();
}
return bos.toByteArray();
}
/**
*
* Description:读取文件内容
*
* @param file
* 文件
* @return String内容
* @throws IOException
* @mail sunyujia@yahoo.cn
* @since：Jun 15, 2008 5:46:32 PM
*/
public static String readFileToString(File file) throws IOException {
StringBuffer sb = null;
BufferedReader in = null;
try {
in = new BufferedReader(new FileReader(file));
sb = new StringBuffer();
for (String line; (line = in.readLine()) != null;) {
sb.append(line + "/r/n");
}
} finally {
if (in != null)
in.close();
}
return sb.toString();
}
/**
*
* Description:复制文件
*
* @param src
* 源文件
* @param dest
* 目标文件
* @param cover
* 是否覆盖
* @throws IOException
* @mail sunyujia@yahoo.cn
* @since：Jun 15, 2008 6:08:28 PM
*/
public static void copyFile(File src, File dest, boolean cover) throws IOException {
FileInputStream in = null;
FileOutputStream out = null;
try {
if (!dest.exists()) {
dest.createNewFile();
} else if (dest.exists() && cover) {
dest.delete();
dest.createNewFile();
} else {
return;
}
in = new FileInputStream(src);
out = new FileOutputStream(dest);
in2OutStream(in, out, BUFFER_SIZE);
} finally {
try {
if (in != null)
in.close();
} finally {
if (out != null)
out.close();
}
}
}
/**
*
* Description:写文件
*
* @param file
* 文件
* @param str
* 内容
* @throws IOException
* @mail sunyujia@yahoo.cn
* @since：Jun 15, 2008 6:17:24 PM
*/
public static void writeFile(File file, String str) throws IOException {
PrintWriter out = null;
BufferedReader in = null;
try {
if (!file.exists())
file.createNewFile();
in = new BufferedReader(new StringReader(str));
out = new PrintWriter(new BufferedWriter(new FileWriter(file)));
for (String line; (line = in.readLine()) != null;) {
out.println(line);
}
} finally {
try {
if (in != null)
in.close();
} finally {
if (out != null)
out.close();
}
}
}
/**
*
* Description:从控制台读取一串字符串
*
* @return 读取的字符串
* @throws IOException
* @mail sunyujia@yahoo.cn
* @since：Jun 15, 2008 6:42:29 PM
*/
public static String readStringFromSystemIn() throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
try {
return br.readLine();
} finally {
if (br != null)
br.close();
}
}
/**
*
* Description:当ObjectInputStream对象调用
* readObject();时,会从ByteArrayInputStream流中反序列化出的对象
*
* @param bi
* @return
* @throws IOException
* @mail sunyujia@yahoo.cn
* @since：Jun 15, 2008 7:07:53 PM
*/
public static ObjectInputStream buildObjectInputStream(ByteArrayInputStream bi) throws IOException {
return new ObjectInputStream(bi);
}
/**
*
* Description:当ObjectOutputStream对象调用
* writeObject(o);时,o对象会序列化到ByteArrayOutputStream流中去
*
* @param bos
* 字节数组流
* @return 对象输出流
* @throws IOException
* @mail sunyujia@yahoo.cn
* @since：Jun 15, 2008 7:06:00 PM
*/
public static ObjectOutputStream buildObjectOutputStream(ByteArrayOutputStream bos) throws IOException {
return new ObjectOutputStream(bos);
}
public static BufferedReader buildBufferedReader(String str) {
return new BufferedReader(new StringReader(str));
}
public static ByteArrayInputStream buildByteArrayInputStream(String str) {
return new ByteArrayInputStream(str.getBytes());
}
public static ByteArrayInputStream buildByteArrayInputStream(byte[] bt) {
return new ByteArrayInputStream(bt);
}
public static void main(String[] args) throws Exception {
byte[] bootFileBytes = IOUtil.readFileToByteArray(new File( "C://boot.ini"));
System.out.println(new String(bootFileBytes));
String bootFileStr = readFileToString(new File("C://boot.ini"));
System.out.println(bootFileStr);
System.out.println(new String(bootFileBytes).equals(bootFileStr));
IOUtil.copyFile(new File("C://boot.ini"), new File("C://boot1.ini"), true);
IOUtil.writeFile(new File("C://boot2.ini"), bootFileStr);
ByteArrayOutputStream bos = new ByteArrayOutputStream();
ObjectOutputStream oos = IOUtil.buildObjectOutputStream(bos);
oos.writeObject(new String("abcd"));
ObjectInputStream ois = IOUtil.buildObjectInputStream(IOUtil.buildByteArrayInputStream(bos.toByteArray()));
System.out.println(ois.readObject());
System.out.println(IOUtil.readStringFromSystemIn());
}
}
本文介绍了一个用于简化Java中文件和流操作的实用工具类。该工具类提供了多种方法，如将输入流复制到输出流、读取文件内容为字符串或字节数组、复制文件等。
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