① java怎么循环读取目录下的文件内容
JAVA 遍历文件夹下的所有文件(递归调用和非递归调用)1.不使用递归的方法调用。public void traverseFolder1(String path) {int fileNum = 0, folderNum = 0;File file = new File(path);if (file.exists()) {LinkedList<File> list = new LinkedList<File>();File[] files = file.listFiles();for (File file2 : files) {if (file2.isDirectory()) {System.out.println("文件夹:" + file2.getAbsolutePath());list.add(file2);fileNum++;} else {System.out.println("文件:" + file2.getAbsolutePath());folderNum++;}}File temp_file;while (!list.isEmpty()) {temp_file = list.removeFirst();files = temp_file.listFiles();for (File file2 : files) {if (file2.isDirectory()) {System.out.println("文件夹:" + file2.getAbsolutePath());list.add(file2);fileNum++;} else {System.out.println("文件:" + file2.getAbsolutePath());folderNum++;}}}} else {System.out.println("文件不存在!");}System.out.println("文件夹共有:" + folderNum + ",文件共有:" + fileNum);}2.使用递归的方法调用public static List<File> getFileList(String strPath) {File dir = new File(strPath);File[] files = dir.listFiles(); // 该文件目录下文件全部放入数组if (files != null) {for (int i = 0; i < files.length; i++) {String fileName = files[i].getName();if (files[i].isDirectory()) { // 判断是文件还是文件夹getFileList(files[i].getAbsolutePath()); // 获取文件绝对路径} else if (fileName.endsWith("avi")) { // 判断文件名是否以.avi结尾String strFileName = files[i].getAbsolutePath();System.out.println("—" + strFileName);filelist.add(files[i]);} else {continue;}}}return filelist;}
② Java 如何读取目录下的文件内容
Java读取目录下的文件内容,使用的是java的文件类,示例如下:
importjava.io.BufferedReader;importjava.io.File;importjava.io.FileInputStream;importjava.io.FileReader;importjava.io.IOException;importjava.io.InputStream;importjava.io.InputStreamReader;importjava.io.RandomAccessFile;importjava.io.Reader;publicclassReadFromFile{/***以字节为单位读取文件,常用于读二进制文件,如图片、声音、影像等文件。**@paramfileName*文件的名*/(StringfileName){Filefile=newFile(fileName);InputStreamin=null;try{System.out.println("以字节为单位读取文件内容,一次读一个字节:");//一次读一个字节in=newFileInputStream(file);inttempbyte;while((tempbyte=in.read())!=-1){System.out.write(tempbyte);}in.close();}catch(IOExceptione){e.printStackTrace();return;}try{System.out.println("以字节为单位读取文件内容,一次读多个字节:");//一次读多个字节byte[]tempbytes=newbyte[100];intbyteread=0;in=newFileInputStream(fileName);ReadFromFile.showAvailableBytes(in);//读入多个字节到字节数组中,byteread为一次读入的字节数while((byteread=in.read(tempbytes))!=-1){System.out.write(tempbytes,0,byteread);}}catch(Exceptione1){e1.printStackTrace();}finally{if(in!=null){try{in.close();}catch(IOExceptione1){}}}}/***以字符为单位读取文件,常用于读文本,数字等类型的文件**@paramfileName*文件名*/(StringfileName){Filefile=newFile(fileName);Readerreader=null;try{System.out.println("以字符为单位读取文件内容,一次读一个字节:");//一次读一个字符reader=newInputStreamReader(newFileInputStream(file));inttempchar;while((tempchar=reader.read())!=-1){//对于windows下,这两个字符在一起时,表示一个换行。//但如果这两个字符分开显示时,会换两次行。//因此,屏蔽掉,或者屏蔽。否则,将会多出很多空行。if(((char)tempchar)!=''){System.out.print((char)tempchar);}}reader.close();}catch(Exceptione){e.printStackTrace();}try{System.out.println("以字符为单位读取文件内容,一次读多个字节:");//一次读多个字符char[]tempchars=newchar[30];intcharread=0;reader=newInputStreamReader(newFileInputStream(fileName));//读入多个字符到字符数组中,charread为一次读取字符数while((charread=reader.read(tempchars))!=-1){//同样屏蔽掉不显示if((charread==tempchars.length)&&(tempchars[tempchars.length-1]!='')){System.out.print(tempchars);}else{for(inti=0;i<charread;i++){if(tempchars[i]==''){continue;}else{System.out.print(tempchars[i]);}}}}}catch(Exceptione1){e1.printStackTrace();}finally{if(reader!=null){try{reader.close();}catch(IOExceptione1){}}}}/***以行为单位读取文件,常用于读面向行的格式化文件**@paramfileName*文件名*/(StringfileName){Filefile=newFile(fileName);BufferedReaderreader=null;try{System.out.println("以行为单位读取文件内容,一次读一整行:");reader=newBufferedReader(newFileReader(file));StringtempString=null;intline=1;//一次读入一行,直到读入null为文件结束while((tempString=reader.readLine())!=null){//显示行号System.out.println("line"+line+":"+tempString);line++;}reader.close();}catch(IOExceptione){e.printStackTrace();}finally{if(reader!=null){try{reader.close();}catch(IOExceptione1){}}}}/***随机读取文件内容**@paramfileName*文件名*/(StringfileName){RandomAccessFilerandomFile=null;try{System.out.println("随机读取一段文件内容:");//打开一个随机访问文件流,按只读方式randomFile=newRandomAccessFile(fileName,"r");//文件长度,字节数longfileLength=randomFile.length();//读文件的起始位置intbeginIndex=(fileLength>4)?4:0;//将读文件的开始位置移到beginIndex位置。randomFile.seek(beginIndex);byte[]bytes=newbyte[10];intbyteread=0;//一次读10个字节,如果文件内容不足10个字节,则读剩下的字节。//将一次读取的字节数赋给bytereadwhile((byteread=randomFile.read(bytes))!=-1){System.out.write(bytes,0,byteread);}}catch(IOExceptione){e.printStackTrace();}finally{if(randomFile!=null){try{randomFile.close();}catch(IOExceptione1){}}}}/***显示输入流中还剩的字节数**@paramin*/(InputStreamin){try{System.out.println("当前字节输入流中的字节数为:"+in.available());}catch(IOExceptione){e.printStackTrace();}}publicstaticvoidmain(String[]args){StringfileName="C:/temp/newTemp.txt";ReadFromFile.readFileByBytes(fileName);ReadFromFile.readFileByChars(fileName);ReadFromFile.readFileByLines(fileName);ReadFromFile.readFileByRandomAccess(fileName);}}
③ java怎么获取一个目录下的所有文件名
获取一个目录下的所有文件和目录方法:
importjava.io.File;publicclassFileTest{publicstaticvoidmain(String[]args){/***将目标目录封装成File对象。*/Filedir=newFile("/Users/zym/Desktop/Mac应用程序");/***获取目录下的所有文件和文件夹*/String[]names=dir.list();for(Stringname:names){System.out.println(name);}}}
通过文件过滤器获取某个目录下的文件,例如所有的 .txt、.doc文件。
过滤器:
importjava.io.File;importjava.io.FilenameFilter;{@Overridepublicbooleanaccept(Filedir,Stringname){returnname.endsWith(".doc");}}
获取某个目录下的按照过滤器规则的所有文件:
importjava.io.File;publicclassFileTest{publicstaticvoidmain(String[]args){/***将目标目录封装成File对象。*/Filedir=newFile("/Users/zym/Desktop/Mac应用程序");/***通过过滤器获取目录下的所有的.doc文件*/String[]names=dir.list(newFilterByDoc());for(Stringname:names){System.out.println(name);}}}
希望能对您有所帮助!
④ java如何取得文件夹下所有的子目录
publicstaticvoidmain(String[]args){Stringpath="D:\";Filefile=newFile(path);File[]tempList=file.listFiles();System.out.println("该目录下对象个数:"+tempList.length);for(inti=0;i<tempList.length;i++){if(tempList[i].isFile()){System.out.println("文件:"+tempList[i]);}if(tempList[i].isDirectory()){System.out.println("文件夹:"+tempList[i]);}}}
推荐个Java从零基础到架构师进阶学习路径及配套教程资料
⑤ 如何查看java读取文件的路径
File类有两个常用方法可以得到文件路径一个是:getCanonicalPath(),另一个是:getAbsolutePath(),可以通过File类的实例调用这两个方法例如.getAbsolutePath()其中file是File的实例对象。下面是一个具体例子:123456789101112131415public class PathTest{public static void main(String[] args){File file = new File(".\\src\\");System.out.println(file.getAbsolutePath());try{System.out.println(file.getCanonicalPath());} catch (IOException e){e.printStackTrace();}}}getAbsolutePath()和getCanonicalPath()的不同之处在于,getCanonicalPath()得到的是一个规范的路径,而getAbsolutePath()是用构造File对象的路径+当前工作目录。例如在上面的例子中.(点号)代表当前目录。getCanonicalPath()就会把它解析为当前目录但是getAbsolutePath()会把它解析成为目录名字(目录名字是点号)。下面是上面程序在我电脑上的输出:G:\xhuoj\konw\.\src\G:\xhuoj\konw\src\
⑥ java怎么读取文件夹下的所有文件
上面方法也可以,我这种直接就可以得到名字,不需要先转版化为File对象Filefile=newFile("D:\\");Stringtest[];test=file.list();for(inti=0;i评论00加载更多权
⑦ Java实现读取某个路径下的文件目录
importjavax.swing.*;
importjavax.swing.table.AbstractTableModel;
importjavax.swing.table.TableCellRenderer;
importjavax.swing.event.TreeModelListener;
importjavax.swing.event.TreeSelectionListener;
importjavax.swing.event.TreeSelectionEvent;
importjavax.swing.tree.TreeModel;
importjavax.swing.tree.TreePath;
importjavax.swing.tree.TreeCellRenderer;
importjava.awt.*;
importjava.awt.event.*;
importjava.io.File;
importjava.io.FileInputStream;
importjava.io.IOException;
importjava.io.FileFilter;
importjava.util.Calendar;
importjava.util.ArrayList;
importjava.text.SimpleDateFormat;
importjava.text.MessageFormat;
/**
*@authorHardneedl
*/
{
=newDimension(300,200);
=newDimension(1024,768);
=newDimension(600,400);
privateJLabelstatusLabel;
privateJTreetree;
privateJTabledetailTable;
;
publicDimensiongetMaximumSize(){returnmaxSize;}
publicDimensiongetMinimumSize(){returnminSize;}
(){returnpreferredSize;}
publicStringgetTitle(){return"JavaExplorer";}
JavaExplorer()throwsHeadlessException{
init();
doLay();
attachListeners();
}
privatevoidinit(){
statusLabel=newJLabel(){publicColorgetForeground(){returnColor.BLUE;}};
tree=newJTree(newFileTreeModel());
tree.setCellRenderer(newDirCellRenderer());
detailTable=newJTable(tableModel=newFileTableModel());
detailTable.getColumnModel().getColumn(2).setCellRenderer(newTableCellRenderer(){
privateJLabellabel=newJLabel();
=newSimpleDateFormat("yyyy年mm月dd日HH时MM分ss秒");
(JTabletable,Objectvalue,booleanisSelected,booleanhasFocus,introw,intcolumn){
if(valueinstanceofCalendar){
Calendarcal=(Calendar)value;
label.setText(format.format(cal.getTime()));
}
returnlabel;
}
});
detailTable.getColumnModel().getColumn(0).setCellRenderer(newTableCellRenderer(){
privateJLabellabel=newJLabel();
(JTabletable,Objectvalue,booleanisSelected,booleanhasFocus,introw,intcolumn){
if(valueinstanceofFile){
Filef=(File)value;
label.setText(f.getName());
label.setForeground(f.isDirectory()?Color.RED:Color.BLACK);
}
returnlabel;
}
});
}
privatevoiddoLay(){
Containercontainer=getContentPane();
jsplitPanesplitPane=newJSplitPane(JSplitPane.HORIZONTAL_SPLIT,newJScrollPane(tree),newJScrollPane(detailTable));
container.add(splitPane,BorderLayout.CENTER);
container.add(statusLabel,BorderLayout.SOUTH);
pack();
}
privatevoidattachListeners(){
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
tree.addTreeSelectionListener(newSelectionListener());
tree.addTreeSelectionListener(new_DirSelectionListener());
DirCellSelectedListenerck=newDirCellSelectedListener(tree);
detailTable.addKeyListener(ck);
detailTable.addMouseListener(ck);
}
publicstaticvoidmain(String[]args){
newJavaExplorer().setVisible(true);
}
{
staticfinalStringroot="我的电脑";
privateFile[]rootFiles;
=newFileFilter(){
publicbooleanaccept(Filef){returnf.isDirectory();}
};
privateFileTreeModel(){rootFiles=File.listRoots();}
publicObjectgetRoot(){returnroot;}
publicObjectgetChild(Objectparent,intindex){
if(parent==getRoot())returnrootFiles[index];
if(parentinstanceofFile){
Filepf=(File)parent;
returnpf.listFiles(dirFilter)[index];
}
returnnull;
}
publicintgetChildCount(Objectparent){
if(parent==getRoot())returnrootFiles.length;
if(parentinstanceofFile){
Filepf=(File)parent;
File[]fs=pf.listFiles(dirFilter);
returnfs==null?0:fs.length;
}
return0;
}
publicbooleanisLeaf(Objectnode){returnfalse;}
publicvoidvalueForPathChanged(TreePathpath,ObjectnewValue){}
(TreeModelListenerl){}
(TreeModelListenerl){}
publicintgetIndexOfChild(Objectparent,Objectchild){
if(parent==getRoot()){
for(inti=0,j=rootFiles.length;i<j;i++)
if(rootFiles[i]==child)returni;
}
if(parentinstanceofFile){
Filepf=(File)parent;
File[]fs=pf.listFiles(dirFilter);
for(inti=0,j=fs.length;i<j;i++){
if(fs[i].equals(child))returni;
}
}
return-1;
}
}
{
publicintgetRowCount(){returndir==null||dir.isFile()?0:dir.listFiles().length;}
publicintgetColumnCount(){return3;}
privateFiledir;
privatevoidsetDir(Filedir){
this.dir=dir;
fireTableDataChanged();
}
publicClass<?>getColumnClass(intcolumnIndex){
switch(columnIndex){
case0:returnFile.class;
case1:returnInteger.class;
case2:returnCalendar.class;
default:returnString.class;
}
}
publicStringgetColumnName(intcolumn){
switch(column){
case0:return"名称";
case1:return"大小";
case2:return"修改日期";
default:return"";
}
}
publicObjectgetValueAt(introwIndex,intcolumnIndex){
File[]fs=dir.listFiles();
Filef=fs[rowIndex];
switch(columnIndex){
case0:returnf;
case1:
if(f.isDirectory())returnnull;
try{
if(f.canRead())
returnnewFileInputStream(f).available();
}catch(IOExceptione){
e.printStackTrace();
}
case2:
Calendarcl=Calendar.getInstance();
cl.setTimeInMillis(f.lastModified());
returncl;
}
returnnull;
}
}
privateclass_{
publicvoidvalueChanged(TreeSelectionEvente){
TreePathpath=e.getNewLeadSelectionPath();
if(path!=null){
Objectobj=path.getLastPathComponent();
if(objinstanceofFile){
Filef=(File)obj;
File[]fs=f.listFiles();
statusLabel.setText(fs==null?null:MessageFormat.format("{0}个文件",fs.length));
}
else
statusLabel.setText(null);
}
}
}
{
publicbooleanisOpaque(){returntrue;}
(JTreetree,Objectvalue,booleanselected,booleanexpanded,booleanleaf,introw,booleanhasFocus){
if(valueinstanceofFile){
Strings=((File)value).getName();
setText(s.isEmpty()?value.toString():s);
}
else
setText(value.toString());
setForeground(selected?Color.BLUE:Color.BLACK);
setBackground(selected?Color.YELLOW:Color.WHITE);
returnthis;
}
}
{
publicvoidvalueChanged(TreeSelectionEvente){
Objectobj=e.getNewLeadSelectionPath().getLastPathComponent();
if(objinstanceofFile){
tableModel.setDir((File)obj);
}
}
}
,MouseListener{
privateJTreetree;
(JTreet){tree=t;}
privatevoidaction(InputEvente){
if(einstanceofMouseEvent){
}
if(einstanceofKeyEvent){
}
}
privatevoidexpand(Filef){
if(f.isDirectory()){
ArrayList<File>L=newArrayList<File>();
L.add(f);
FileparentFile=f.getParentFile();
while(parentFile!=null){
L.add(parentFile);
parentFile=parentFile.getParentFile();
}
TreePathtreePath=newTreePath(FileTreeModel.root);
for(inti=L.size()-1;i>-1;i–){
treePath=treePath.pathByAddingChild(L.get(i));
}
tree.setSelectionPath(treePath);
}
}
publicvoidkeyTyped(KeyEvente){}
publicvoidkeyPressed(KeyEvente){
if(e.getKeyCode()!=KeyEvent.VK_ENTER)return;
if(e.getSource()==detailTable){
introw=detailTable.getSelectedRow();
if(row!=-1){
Filef=(File)detailTable.getValueAt(row,0);
expand(f);
}
}
}
publicvoidkeyReleased(KeyEvente){
}
publicvoidmouseClicked(MouseEvente){
if(e.getClickCount()==2){
if(e.getSource()==detailTable){
introw=detailTable.getSelectedRow();
if(row!=-1){
Filef=(File)detailTable.getValueAt(row,0);
expand(f);
}
}
}
}
publicvoidmousePressed(MouseEvente){
}
publicvoidmouseReleased(MouseEvente){
}
publicvoidmouseEntered(MouseEvente){
}
publicvoidmouseExited(MouseEvente){
}
}
}
⑧ java中在怎么读取文件夹中的内容
以下java程序的作用是将当前目录及其子目录中的.java文件收集到collection.txt文件中,并添加行号,你可以参考一下。import java.io.*;public class Collection{public static void main(String[] args) throws Exception{final String F=".\\collection.txt";FW=new FileWriter(new File(F));Collection.ProcessDirectory(new File("."));Collection.FW.flush();Collection.FW.close();}private static void ProcessDirectory(File d) throws Exception{File[] ds=null;Collection.ProcessJavaFile(d);ds=d.listFiles(Collection.DFilter);for(int i=0;i<ds.length;i++){Collection.ProcessDirectory(ds[i]);}}private static void ProcessJavaFile(File d) throws Exception{String line=null;LineNumberReader lnr=null;File[] fs=d.listFiles(Collection.FNFilter);for(int i=0;i<fs.length;i++){lnr=new LineNumberReader(new FileReader(fs[i]));Collection.FW.write(fs[i].getCanonicalPath()+"\r\n");System.out.println(fs[i].getCanonicalPath());while(null!=(line=lnr.readLine())){Collection.FW.write(""+lnr.getLineNumber()+" "+line+"\r\n");System.out.println(""+lnr.getLineNumber()+" "+line);}Collection.FW.write("\r\n");System.out.println();}}private static FileWriter FW;private static FilenameFilter FNFilter=new FilenameFilter(){public boolean accept(File dir,String name){return name.endsWith(".java");}};private static FileFilter DFilter=new FileFilter(){public boolean accept(File pathname){return pathname.isDirectory();}};}
⑨ JAVA怎么从一个目录中依次读取所有文件
File f = new File(path);File[] t = f.listFiles(); 这个方法来读取这个目录下的文件 。
⑩ java读取文件路径问题
如果你使用的是eclipse,请检查编译是否禁止了非.class文件的编译输出,如果这项没有问题。那么 src/META-INF/*.* 文件自动输出到 /WEB-INF/classes/META-INF/*.*。也就是说,最终资源文件在 WEB-INF/classes/META-INF/weibo.xml
使用JAVA 类获取路径:
Filef=newFile(getClass().getResource("/META-INF/weibo.xml").getPath());
获取InputStream:
InputStreaminput=getClass().getResourceAsStream("/META-INF/weibo.xml");
另外,JAVA项目的标准协定(习惯)中的源代码目录结构是:
src|–main||–javaJAVA文件||–resources资源文件|–test|–javaTESTJAVA文件|–resourcesTEST资源文件
输出的目录结构是:
target|–classesmain/java,main/resource输出目录|–test-classestest/java,test/resources输出目录