IO--int read(char cbuf[],int off,int len)
1.InputStreamReader
Reader与Writer是基于字符的IO操作接口，而InputStreamReader的read方法就是以字符为单位的读方法
/**
* Reads characters into a portion of an array.
*
* @param cbuf Destination buffer
* @param offset Offset at which to start storing characters
* @param length Maximum number of characters to read
*
* @return The number of characters read, or -1 if the end of the
* stream has been reached
*
* @exception IOException If an I/O error occurs
*/
public int read(char cbuf[], int offset, int length) throws IOException {
return sd.read(cbuf, offset, length);
}
三个参数：cbuf[]是char数组用于储存读到的字符，offset是指从cbuf[]第几位开始储存而不是指从读文件第几个字符开始读，length指每次读多少位
使用例程
package IO;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
public class testReader {
public static void main(String argv[]){new testReader().testRead();}
public void testRead(){
try{
StringBuffer sb=new StringBuffer();
char[] cBuf=new char[1024];
File file=new File("D:\\javaCode\\testSE\\src\\IO\\file.txt");
if(!file.exists()){
System.out.println("not exists");
return;
}
FileReader f=new FileReader(file);
while(f.read(cBuf,10,2)>0){
sb.append(cBuf);
System.out.println(sb);
}
}catch (IOException e){
e.printStackTrace();
}
}
}
