java 文件读写_FileReader

package test;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
public class Test {
 public static void main(String arg[]) {
  String fileName = "E:\\share\\test.txt";
  String writeData = "HelloWorld!\r\nnihao我的内存是3G的 ";
  File file = new File(fileName);
  if(file.exists()){
   file.delete();
  }
  
  char[] byteOutData = writeData.toCharArray();
  char[] byteInData = new char[50];
  int length = 0;
  
  try {
   file.createNewFile();
   if(file.exists() && file.canWrite()){
    FileWriter fileWrite = new FileWriter(file);
    fileWrite.write(byteOutData);
    fileWrite.close();
   }
   if (file.exists() && file.canRead()) {
    FileReader fileReader = new FileReader(file);
    while((length = fileReader.read(byteInData)) !=-1){
     System.out.print(new String(byteInData,0,length));
    }
     fileReader.close();
   }
  } catch (IOException e) {
   System.out.println("IOException occur");
   e.getMessage();
  }
 }
}