Java io流详解三

public  class  IOpractise  {


public  void    iotest()  {
int  b=  0;
FileInputStream  fis  =  null;
try  {
fis  =  new  FileInputStream("C:\Users\wb-cjz286752\Desktop\小程序.txt");
}  catch  (FileNotFoundException  e)  {
e.printStackTrace();
System.out.println("系统找不到指定文件!");
System.exit(-1);

}

long  num  =0;
try  {
while((b=fis.read())!=-1){
//System.out.println((char)b);
System.out.println(b);
num++;
}
fis.close();
System.out.println();
System.out.println("总共读了"+num  +  "个字节的文件");
}  catch  (IOException  e)  {    
e.printStackTrace();
System.out.println("文件读取错误!");
}

}


public  void  iotest1()  throws  IOException{

try  {
FileInputStream  fis  =  new  FileInputStream("C:\Users\wb-cjz286752\Desktop\小程序.txt");
int  read  =  0;
while((read=fis.read())!=-1){
System.out.println(read);    
}
fis.close();
}  catch  (FileNotFoundException  e)  {
//  TODO  Auto-generated  catch  block
e.printStackTrace();
}

}

public  String  iotest2()  throws  IOException{
StringBuffer  result  =  new  StringBuffer();

try  {
BufferedReader  bf  =  new  BufferedReader(new  FileReader("C:\Users\wb-cjz286752\Desktop\webelement.txt"));
String  str  =  null;
while  ((str=bf.readLine())!=null){
result.append(str);
//System.out.println(result);    
}
bf.close();
}  catch  (FileNotFoundException  e)  {
e.printStackTrace();
}
return  result.toString();
}


public  void  iotest3(String  filename)  throws  IOException{
StringBuffer  result  =  new  StringBuffer();
try  {
BufferedReader  br  =  new  BufferedReader(new  FileReader(filename));
String  str  =  null;
while((str=br.readLine())!=null){
result.append(System.lineSeparator()+str);
//System.out.println();
}
b r.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(result.toString());

}

public void iotest4() throws IOException{
try {
FileWriter fw = new FileWriter("C:\Users\wb-cjz286752\Desktop\1111111111111.txt");

fw.write("123llove");
fw.flush();
fw.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

try {
FileReader fr = new FileReader("C:\Users\wb-cjz286752\Desktop\1111111111111.txt");
int it =0;
while((it=fr.read())!=-1){
System.out.print((char)it);

}
fr.close();

} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

public void iotest5(){
try {
FileReader fr = new FileReader("C:\Users\wb-cjz286752\Desktop\webelement.txt");
int it =0;
char[] buf = new char[10];
StringBuilder sb = new StringBuilder();
try {
while((it=fr.read(buf))!=-1){
sb.append(new String(buf,0,it));
}
String str = sb.toString();
System.out.println(str);
fr.close();

} catch (IOException e) {
e.printStackTrace();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}

}

public void iotest6() throws IOException{
FileWriter fw = new FileWriter("C:\Users\wb-cjz286752\Desktop\1111111111111.txt",true);
try {
fw.write("1234567890testtest!!!!!!!");
fw.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

public void iotest7(){
try {
FileReader fr = new FileReader("C:\Users\wb-cjz286752\Desktop\1111111111111.txt");
FileWriter fw = new FileWriter("C:\Users\wb-cjz286752\Desktop\2222222222222.txt");
char [] buf = new char[2];
int it =0;
while ((it=fr.read(buf))!=-1){
String str = new String(buf,0,it);
fw.write(str);
}
fw.flush();
fw.close();
fr.close();

} catch (IOException e) {
e.printStackTrace();
}

}

public void iotest8() throws IOException{
try {
FileReader fr = new FileReader("C:\Users\wb-cjz286752\Desktop\2222222222222.txt");
BufferedReader br = new BufferedReader(fr);
String str = null;
StringBuilder sb = new StringBuilder();
while ((str=br.readLine())!=null){
sb.append(str);
}
br.close();
System.out.println(sb.toString());

} catch (FileNotFoundException e) {
e.printStackTrace();
}
}

public void iotest9() throws IOException{
try {
BufferedReader br = new BufferedReader(new FileReader("C:\Users\wb-cjz286752\Desktop\2222222222222.txt"));
BufferedWriter bw = new BufferedWriter(new FileWriter("C:\Users\wb-cjz286752\Desktop\3333333333333.txt"));
String str = null;
while ((str=br.readLine())!=null){
bw.write(str);
bw.newLine();
}
bw.flush();
bw.close();
br.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}

public void iotest10() throws IOException{
try {
FileInputStream fis = new FileInputStream("C:\Users\wb-cjz286752\Desktop\3333333333333.txt");
FileOutputStream fos = new FileOutputStream("C:\Users\wb-cjz286752\Desktop\4444444444444.txt");
int it = 0;
byte[] byt = new byte[1024];
while ((it=fis.read(byt))!=-1){
fos.write(byt,0 ,it);
}
fos.flush();
fos.close();
fis.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
}

}

public static void main(String[] args) throws IOException {
IOpractise iop = new IOpractise();
//iop.iotest3("C:\Users\wb-cjz286752\Desktop\webelement.txt");
iop.iotest10();
}


}
原文地址:https://www.cnblogs.com/111testing/p/8099938.html