Commons_IO_FileUtils的使用

commos_io.jar包下载地址：http://commons.apache.org/proper/commons-io/download_io.cgi

官方文档地址：http://commons.apache.org/proper/commons-io/javadocs/api-release/index.html

---

//文件、目录遍历 

1 package commosIO;

 import java.io.File;
 import java.util.Collection;

 import org.apache.commons.io.FileUtils;
 import org.apache.commons.io.filefilter.DirectoryFileFilter;
 import org.apache.commons.io.filefilter.EmptyFileFilter;
 import org.apache.commons.io.filefilter.FileFilterUtils;
 import org.apache.commons.io.filefilter.SuffixFileFilter;

 public class CommosIOTest1 {
     public static void main(String[] args) {
         //文件或目录的大小
         long len = FileUtils.sizeOf(new File("src/commosIO/CommosIOTest1.java"));
         long len2 = FileUtils.sizeOf(new File("F:/EclipseWorkspace/Java300"));
         System.out.println(len);
         System.out.println(len2);
         System.out.println("-----------------------------");

         //列出目录下的文件  具体查看api文档
         Collection<File> c = FileUtils.listFiles(new File("F:/EclipseWorkspace/Java300"),
                 EmptyFileFilter.NOT_EMPTY,DirectoryFileFilter.INSTANCE);
         for(File temp:c) {
             System.out.println(temp.getAbsolutePath());
         }

         //只列出后缀为java的文件  文件过滤
         System.out.println("-----------------------------");
         Collection<File> c2 = FileUtils.listFiles(new File("F:/EclipseWorkspace/Java300"),
                 new SuffixFileFilter(".java"),DirectoryFileFilter.INSTANCE);
         for(File temp:c2) {
             System.out.println(temp.getAbsolutePath());
         }

         System.out.println("-----------------------------");
         Collection<File> c3 = FileUtils.listFiles(new File("F:/EclipseWorkspace/Java300"),
                 FileFilterUtils.or(new SuffixFileFilter(".java"),new SuffixFileFilter(".txt")),
                     DirectoryFileFilter.INSTANCE);
         for(File temp:c3) {
             System.out.println(temp.getAbsolutePath());
         }
     }
 }

输出：

---

1659
6089568
-----------------------------
F:\EclipseWorkspace\Java300\.classpath
F:\EclipseWorkspace\Java300\.project
F:\EclipseWorkspace\Java300\.settings\org.eclipse.jdt.core.prefs
F:\EclipseWorkspace\Java300\a-coyp.jpg
F:\EclipseWorkspace\Java300\a.jpg
F:\EclipseWorkspace\Java300\b.jpg
F:\EclipseWorkspace\Java300\bin\commosIO\CommosIOTest1.class
F:\EclipseWorkspace\Java300\bin\commosIO\CommosIOTest2.class
F:\EclipseWorkspace\Java300\bin\commosIO\CommosIOTest3.class
F:\EclipseWorkspace\Java300\bin\ioStudy\Coffee.class
F:\EclipseWorkspace\Java300\bin\ioStudy\Copy.class
F:\EclipseWorkspace\Java300\bin\ioStudy\Decorate.class
F:\EclipseWorkspace\Java300\bin\ioStudy\DecorateStudy1.class
F:\EclipseWorkspace\Java300\bin\ioStudy\DirStudy.class
F:\EclipseWorkspace\Java300\bin\ioStudy\Drink.class
F:\EclipseWorkspace\Java300\bin\ioStudy\IOstudy1.class
F:\EclipseWorkspace\Java300\bin\ioStudy\IOstudy2.class
F:\EclipseWorkspace\Java300\bin\ioStudy\IOstudy3.class
F:\EclipseWorkspace\Java300\bin\ioStudy\IOstudy4.class
F:\EclipseWorkspace\Java300\bin\ioStudy\IOstudy5.class
F:\EclipseWorkspace\Java300\bin\ioStudy\IOstudy6.class
F:\EclipseWorkspace\Java300\bin\ioStudy\IOstudy7.class
F:\EclipseWorkspace\Java300\bin\ioStudy\Milk.class
F:\EclipseWorkspace\Java300\bin\ioStudy\Sugar.class
F:\EclipseWorkspace\Java300\bin\test\stringTest\ArrayCopy1.class
F:\EclipseWorkspace\Java300\bin\test\stringTest\MyArrayList.class
F:\EclipseWorkspace\Java300\bin\test\stringTest\MyHashMap.class
F:\EclipseWorkspace\Java300\bin\test\stringTest\Node.class
F:\EclipseWorkspace\Java300\bin\test\stringTest\TestBubbleSort.class
F:\EclipseWorkspace\Java300\bin\test\stringTest\TestCollection.class
F:\EclipseWorkspace\Java300\bin\test\stringTest\TestString.class
F:\EclipseWorkspace\Java300\commons-io-2.6-sources.jar
F:\EclipseWorkspace\Java300\commons-io-2.6.jar
F:\EclipseWorkspace\Java300\order.txt
F:\EclipseWorkspace\Java300\output.txt
F:\EclipseWorkspace\Java300\src\commosIO\CommosIOTest1.java
F:\EclipseWorkspace\Java300\src\commosIO\CommosIOTest2.java
F:\EclipseWorkspace\Java300\src\commosIO\CommosIOTest3.java
F:\EclipseWorkspace\Java300\src\ioStudy\Copy.java
F:\EclipseWorkspace\Java300\src\ioStudy\DecorateStudy1.java
F:\EclipseWorkspace\Java300\src\ioStudy\DirStudy.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy1.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy2.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy3.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy4.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy5.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy6.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy7.java
F:\EclipseWorkspace\Java300\src\test\stringTest\ArrayCopy1.java
F:\EclipseWorkspace\Java300\src\test\stringTest\MyArrayList.java
F:\EclipseWorkspace\Java300\src\test\stringTest\MyHashMap.java
F:\EclipseWorkspace\Java300\src\test\stringTest\TestBubbleSort.java
F:\EclipseWorkspace\Java300\src\test\stringTest\TestCollection.java
F:\EclipseWorkspace\Java300\src\test\stringTest\TestString.java
F:\EclipseWorkspace\Java300\temp\a.jpg
F:\EclipseWorkspace\Java300\test.txt
F:\EclipseWorkspace\Java300\testcopy.txt
-----------------------------
F:\EclipseWorkspace\Java300\src\commosIO\CommosIOTest1.java
F:\EclipseWorkspace\Java300\src\commosIO\CommosIOTest2.java
F:\EclipseWorkspace\Java300\src\commosIO\CommosIOTest3.java
F:\EclipseWorkspace\Java300\src\ioStudy\Copy.java
F:\EclipseWorkspace\Java300\src\ioStudy\DecorateStudy1.java
F:\EclipseWorkspace\Java300\src\ioStudy\DirStudy.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy1.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy2.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy3.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy4.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy5.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy6.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy7.java
F:\EclipseWorkspace\Java300\src\test\stringTest\ArrayCopy1.java
F:\EclipseWorkspace\Java300\src\test\stringTest\MyArrayList.java
F:\EclipseWorkspace\Java300\src\test\stringTest\MyHashMap.java
F:\EclipseWorkspace\Java300\src\test\stringTest\TestBubbleSort.java
F:\EclipseWorkspace\Java300\src\test\stringTest\TestCollection.java
F:\EclipseWorkspace\Java300\src\test\stringTest\TestString.java
-----------------------------
F:\EclipseWorkspace\Java300\order.txt
F:\EclipseWorkspace\Java300\output.txt
F:\EclipseWorkspace\Java300\src\commosIO\CommosIOTest1.java
F:\EclipseWorkspace\Java300\src\commosIO\CommosIOTest2.java
F:\EclipseWorkspace\Java300\src\commosIO\CommosIOTest3.java
F:\EclipseWorkspace\Java300\src\ioStudy\Copy.java
F:\EclipseWorkspace\Java300\src\ioStudy\DecorateStudy1.java
F:\EclipseWorkspace\Java300\src\ioStudy\DirStudy.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy1.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy2.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy3.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy4.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy5.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy6.java
F:\EclipseWorkspace\Java300\src\ioStudy\IOstudy7.java
F:\EclipseWorkspace\Java300\src\test\stringTest\ArrayCopy1.java
F:\EclipseWorkspace\Java300\src\test\stringTest\MyArrayList.java
F:\EclipseWorkspace\Java300\src\test\stringTest\MyHashMap.java
F:\EclipseWorkspace\Java300\src\test\stringTest\TestBubbleSort.java
F:\EclipseWorkspace\Java300\src\test\stringTest\TestCollection.java
F:\EclipseWorkspace\Java300\src\test\stringTest\TestString.java
F:\EclipseWorkspace\Java300\test.txt
F:\EclipseWorkspace\Java300\testcopy.txt

---

文件读写

 1 package commosIO;

 import java.io.File;
 import java.io.IOException;
 import java.util.List;

 import org.apache.commons.io.FileUtils;

 public class CommosIOTest2 {
     public static void main(String[] args) throws IOException {
         //读取文件
         String s = FileUtils.readFileToString(new File("output.txt") , "GBK");
         System.out.println(s);
         System.out.println("-----------------");
         byte[] datas = FileUtils.readFileToByteArray(new File("output.txt"));
         System.out.println(datas.length);
         System.out.println("-----------------");
         //逐行读取
         List<String> list = FileUtils.readLines(new File("output.txt"),"GBK");
         for(String temp:list) {
             System.out.println(temp);
         }
         System.out.println("-----------------");
         //写文件  追加
         FileUtils.write(new File("output.txt"), "锄禾日当午\r\n","GBK");
         FileUtils.write(new File("output.txt"), "汗滴禾下土","GBK",true);
     }
 }

输出：

锄禾日当午
汗滴禾下土
-----------------
22
-----------------
锄禾日当午
汗滴禾下土
-----------------

---

文件拷贝

 1 package commosIO;

 import java.io.File;
 import java.io.IOException;
 import java.net.URL;

 import org.apache.commons.io.FileUtils;
 import org.apache.commons.io.IOUtils;

 public class CommosIOTest3 {
     public static void main(String[] args) throws IOException {
         //复制文件
         FileUtils.copyFile(new File("a.jpg"), new File("a-coyp.jpg"));
         //复制文件到目录
         FileUtils.copyFileToDirectory(new File("a.jpg"), new File("temp"));
         //复制目录到目录
         //复制目录等  查看文档  大同小异

         //拷贝url内容
         FileUtils.copyURLToFile(new URL("http://www.baidu.com"), new File("order.txt"));

         String datas = IOUtils.toString(new URL("http://www.baidu.com"),"UTF-8");
         System.out.println(datas);
     }
 }