java----commons-io
maven
<dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.6</version> </dependency>
FileUtils
遍历
public static void main(String[] args) throws IOException { //l可以是文件大小也可以是目录大小 //long l = FileUtils.sizeOf(new File("xx.txt")); //System.out.println(l); //列出子子孙孙的目录和文件 //Collection<File> files = FileUtils.listFilesAndDirs(new File("C:\\Users\\zhengyan\\Desktop\\springframework"), EmptyFileFilter.EMPTY, DirectoryFileFilter.INSTANCE); //for (File f:files) { //System.out.println(f); //} //列出文件和目录(可以为空) DirectoryFileFilter.DIRECTORY:子子孙孙,如果是null,表示只有第一层 Collection<File> files = FileUtils.listFilesAndDirs(new File("C:\\Users\\zhengyan\\Desktop\\test"), EmptyFileFilter.EMPTY, DirectoryFileFilter.DIRECTORY); for (File f:files) { System.out.println(f); } //列出文件 Collection<File> files1 = FileUtils.listFiles(new File("C:/Users/zhengyan/Desktop/test"), EmptyFileFilter.EMPTY, DirectoryFileFilter.DIRECTORY); for (File x:files1) { System.out.println(x); } //更多组合 files = FileUtils.listFilesAndDirs(new File("C:\\Users\\zhengyan\\Desktop\\test"), FileFilterUtils.or(new SuffixFileFilter("java"),EmptyFileFilter.NOT_EMPTY), DirectoryFileFilter.DIRECTORY); }
文件读取
public static void main(String[] args) throws IOException { String s = FileUtils.readFileToString(new File("C:\\Users\\zhengyan\\Desktop\\script.txt"),"utf-8"); System.out.println(s); byte[] bytes = FileUtils.readFileToByteArray(new File("C:\\Users\\zhengyan\\Desktop\\script.txt")); //逐行读取 List<String> strings = FileUtils.readLines(new File("C:\\Users\\zhengyan\\Desktop\\script.txt"), "utf-8"); }
文件写入
public static void main(String[] args) throws IOException { FileUtils.writeStringToFile(new File("a.txt"),"xx","utf-8"); FileUtils.writeByteArrayToFile(new File("a.txt"),"xx".getBytes("utf-8"),true); //写入列表 ArrayList<String> strings = new ArrayList<>(); strings.add("1"); strings.add("2"); strings.add("3"); //--:列表中的每一个元素的连接符 FileUtils.writeLines(new File("a.txt"),strings,"--",false); }
文件copy
public static void main(String[] args) throws IOException { //方式1 //byte[] bytes = FileUtils.readFileToByteArray(new File("a.txt")); //FileUtils.writeByteArrayToFile(new File("b.txt"),bytes); //FileUtils.copyURLToFile(new URL("http://www.baidu.com"),new File("a.txt")); //文件的copy //FileUtils.copyFile(new File("a.txt"),new File("a-copy.txt")); //copy文件到目录 //FileUtils.copyFileToDirectory(); //copy目录到目录 //FileUtils.copyDirectoryToDirectory(); //将目录中的文件copy到目录中 //FileUtils.copyDirectory(); //下载url源码 //String s = IOUtils.toString(new URL("http://www.163.com"), "gbk"); }
IOUtils
//将htmlContent内容转成输入流 InputStream inputStream = IOUtils.toInputStream(htmlContent, "utf-8");