使用org.apache.commons.io.FileUtils,IOUtils;工具类操作文件

转自：http://blog.csdn.net/z69183787/article/details/8097573#

Commons IO是apache的一个开源的工具包,封装了IO操作的相关类,使用Commons IO可以很方便的读写文件,

FileUtils 中提供了许多设计文件操作的 已封装好的方法。

IOUtils 则是提供了读写文件的方法。

File src = new File("G:/2012/portal/login.jsp");
File tar = new File("G:/2012/portal/loginZs.jsp");
File tarDir = new File("G:/2012/portal/center/");

FileUtils.copyFile(src,tar);//复制文件
FileUtils.copyFileToDirectory(src, tarDir);//复制文件到指定文件夹

读取文件：

// by FileUtils  
List lines = FileUtils.readLines(file, "UTF-8");  

// by IOUtils  
List lines = IOUtils.readLines(new FileInputStream(file), "UTF-8");  

写入文件：

// by FileUtils  
FileUtils.writeLines(file, "UTF-8", lines);  

// by IOUtils  
IOUtils.writeLines(lines, null, new FileOutputStream(file));  

案例：

public class IoTest {  

    /** 
     * @param args 
     */  
    public static void main(String[] args) throws Exception {  
        // 输入流复制到 输出流 
        Writer write = new FileWriter("c:\\kk.dat");  

        InputStream ins = new FileInputStream(new File("c:\\text.txt"));  

        IOUtils.copy(ins, write);  
        write.close();  

        ins.close();  

        //文本写入指定文件 
        String name = "my name is panxiuyan";  

        File file =  new File("c:\\name.txt");  

        FileUtils.writeStringToFile(file, name);  

        //将输入流转换成文本 

        URL url = new URL("http://www.dimurmill.com");  

        InputStream ins = url.openStream();  

        String contents = IOUtils.toString(ins,"UTF-8");  
        System.out.println( "Slashdot: " + contents );  

            //关闭相关流
             File file = null;  

        InputStream ins = null;  
        try{  
            file = new File("C:\\Test.java");  

            ins = new FileInputStream(file);  
        }catch(Exception e){  
            e.printStackTrace();  
        }finally{  
            IOUtils.closeQuietly(ins);  
        }  


        }

        //文件复制
        File srcfile = new File("c:\\Test.java");    
        File destfile = new File("c:\\Test.java.bak");    
        FileUtils.copyFile(srcfile, destfile);    

        //文件复制指定的目录 
        File srcfile = new File("c:\\Test.java");    
        File destDir = new File("D:\\");  
        FileUtils.copyFileToDirectory(srcfile, destDir);  

        //网络流保存为文件
    URL url = new URL("http://www.163.com");   
        File file = new File("c:\\163.html");      
        FileUtils.copyURLToFile(url, file);  

        //文件目录操作 
        File dir = new File("c:\\test");  
        FileUtils.cleanDirectory(dir);//清空目录下的文件  
        FileUtils.deleteDirectory(dir);//删除目录和目录下的文件 

        //目录大小  
        long size = FileUtils.sizeOfDirectory(dir);  

        //目录操作
        File testFile = new File( "testFile.txt" );  
        //如果不存在,新建  
        // 如果存在,修改文件修改时间  
        FileUtils.touch( testFile );  
        //记录流的读取写入字节数 
        File test = new File( "test.dat" );  
        //输出流的统计  
    CountingOutputStream countStream = null;  
    //输入流的统计  
    //CountingInputStream countStream = null;  
    try {  
            FileOutputStream fos = new FileOutputStream( test );          
        countStream = new CountingOutputStream( fos );  
        countStream.write( "Hello".getBytes( ) );  
        } catch( IOException ioe ) {  
            System.out.println( "Error writing bytes to file." );  
        } finally {       
            IOUtils.closeQuietly( countStream );    
        }  

        if( countStream != null ) {  
             int bytesWritten = countStream.getCount( );  
             System.out.println( "Wrote " + bytesWritten + " bytes to test.dat" );  
        }  

        //相同的内容写入不同的文本 
        File test1 = new File("split1.txt");  
                File test2 = new File("split2.txt");  
        OutputStream outStream = null;  
        try {  
            FileOutputStream fos1 = new FileOutputStream( test1 );  
            FileOutputStream fos2 = new FileOutputStream( test2 );  
            //包含不同的文本  
            outStream = new TeeOutputStream( fos1, fos2 );  
            outStream.write( "One Two Three, Test".getBytes( ) );  
            outStream.flush( );       
        } catch( IOException ioe ) {      
            System.out.println( "Error writing to split output stream" );         
        } finally {           
            IOUtils.closeQuietly( outStream );            
            } 
         }  

}