java 文件读写的有用工具

java 文件读写的有用工具

package org.rui.io.util;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.TreeSet;
/**
 * 文件读写的有用工具
 * @author lenovo
 *
 */
public class TextFile  extends ArrayList<String>{

	//读取一个文件，并返回字符串
	public static String read(String fileName)
	{
		StringBuilder sb=new StringBuilder();

		try {
			BufferedReader in=new BufferedReader(
					new FileReader(
							new File(fileName).getAbsoluteFile())// 返回此抽象路径名的绝对路径名形式。
					);

			try {
				String s;
				while((s=in.readLine())!=null)
					sb.append(s);
					sb.append("\n");

			} finally
			{
				in.close();
			}
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
		return sb.toString();
	}
	// write a single
	public static void write(String fileName,String text)
	{
		try {
			PrintWriter out=new PrintWriter(
					new File(fileName).getAbsoluteFile()
					);
			try {
				out.print(text);

			}finally
			{
				out.close();
			}
		} catch (Exception e) {
			throw new RuntimeException(e);
		}

	}

	// read a file
	public TextFile(String fileName,String splitter)
	{
		//放入集合，
		super(Arrays.asList(read(fileName).split(splitter)));
		if(get(0).equals("")) remove(0);
	}

	public TextFile(String fileName)
	{
		//重载当前构造器
		this(fileName,"\n");
	}

	public void write(String fileName)
	{
		try {
			PrintWriter out=new PrintWriter(
					new File(fileName).getAbsoluteFile()
					);
			try {
				for(String item:this){
					//System.out.println(item);
					 out.println(item);
				}

			} finally
			{
				out.close();
			}
		} catch (Exception e) {
			throw new RuntimeException(e);
		}

	}
	/////simple test
	public static void main(String[] args) {
		//路径依据自已的改
		String path="D:\\Users\\liangrui\\workspace\\thinking\\src\\org\\rui\\io\\util/";

		String fileText =read(path+"TextFile.java");//读取当前java文本
		//写入文件
		write(path+"newText.txt",fileText);
		//对象 写
		TextFile tf=new TextFile(path+"newText.txt");//再次读取写入的新文本
		tf.write(path+"newText2.txt");//再次写入

		//读取文本并放入TreeSet集合中
		TreeSet<String> words=new TreeSet<String>(
				new TextFile(path+"TextFile.java","\\W+")//\W词字符
				);
		//headSet 返回此 set 的部分视图，其元素严格小于  toElement。
		System.out.println(words.headSet("a"));

	}
}
/**
 * output:
[0, ArrayList, Arrays, BufferedReader, D, Exception, File,
FileReader, PrintWriter, RuntimeException, String, StringBuilder,
System, TextFile, TreeSet, Users, W]
 */

package org.rui.io.util;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

/**
 * 读取二进制文件
 * @author lenovo
 *
 */
public class BinaryFile {

	public static byte[] read(File bFile) throws IOException
	{
		BufferedInputStream bis=new BufferedInputStream(
				new FileInputStream(bFile)
				);
		try {
			//产生恰当数组尺寸
			byte[] data=new byte[bis.available()];
			bis.read(data);
			return data;
		} finally
		{
			bis.close();
		}
	}

	public static byte[] read(String bF) throws IOException
	{
		//重载
		return read(new File(bF).getAbsoluteFile());// getAbsoluteFile 返回此抽象路径名的绝对路径名形式。
	}

}