????1????????????????
????2?????????????????
????3?????ж?????????
????4???????????????
????[Java]?????????????
????publicclassReadFromFile{
????/**
????*????????λ??????????????????????????????????????????????
????*/
????publicstaticvoidreadFileByBytes(StringfileName){
????Filefile=newFile(fileName);
????InputStreamin=null;
????try{
????System.out.println("????????λ?????????????ζ????????");
????//??ζ???????
????in=newFileInputStream(file);
????inttempbyte;
????while((tempbyte=in.read())!=-1){
????System.out.write(tempbyte);
????}
????in.close();
????}catch(IOExceptione){
????e.printStackTrace();
????return;
????}
????try{
????System.out.println("????????λ?????????????ζ????????");
????//??ζ???????
????byte[]tempbytes=newbyte[100];
????intbyteread=0;
????in=newFileInputStream(fileName);
????ReadFromFile.showAvailableBytes(in);
????//??????????????????У?byteread???ζ?????????
????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){
????}
????}
????}
????}
????/**
????*????????λ?????????????????????????????????
????*/
????publicstaticvoidreadFileByChars(StringfileName){
????Filefile=newFile(fileName);
????Readerreader=null;
????try{
????System.out.println("????????λ?????????????ζ????????");
????//??ζ???????
????reader=newInputStreamReader(newFileInputStream(file));
????inttempchar;
????while((tempchar=reader.read())!=-1){
????//????windows?￡? ??????????????????????????С?
????//??????????????????????????????С?
????//???????ε? ?????????? ?????????????????С?
????if(((char)tempchar)!=' '){
????System.out.print((char)tempchar);
????}
????}
????reader.close();
????}catch(Exceptione){
????e.printStackTrace();
????}
????try{
????System.out.println("????????λ?????????????ζ????????");
????//??ζ???????
????char[]tempchars=newchar[30];
????intcharread=0;
????reader=newInputStreamReader(newFileInputStream(fileName));
????//???????????????????У?charread???ζ???????
????while((charread=reader.read(tempchars))!=-1){
????//??????ε? ?????
????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){
????}
????}
????}
????}
????/**
????*???????λ????????????????????е????????
????*/
????publicstaticvoidreadFileByLines(StringfileName){
????Filefile=newFile(fileName);
????BufferedReaderreader=null;
????try{
????System.out.println("???????λ?????????????ζ?????У?");
????reader=newBufferedReader(newFileReader(file));
????StringtempString=null;
????intline=1;