java dataoutputstream_java 数据流DataOutputStream和DataInputstream
应用实例
import java.io.*;
public class DataStreamDemo
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public static void main(String[] args)
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try
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DataOutputStream out=new DataOutputStream(new FileOutputStream("F:\\workspace\\JavaPrj\\test.txt"));
double[] prices={18.99,9.22,14.22,5.22,4.21};
int[] units={10,10,20,39,40};
String[] descs={"bike","book","boat","boot","bus"};
for(int i=0;i
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try
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out.writeDouble(prices[i]);
out.writeChar('\t');
out.writeInt(units[i]);
out.writeChar('\t');
out.writeChars(descs[i]);
out.writeChar('\n');
}
catch (IOException e)
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// TODO Auto-generated catch block
e.printStackTrace();
}
}
try
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out.close();
}
catch (IOException e)
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// TODO Auto-generated catch block
e.printStackTrace();
}
}
catch (FileNotFoundException e)
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// TODO Auto-generated catch block
e.printStackTrace();
}
try
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DataInputStream in=new DataInputStream(new FileInputStream("F:\\workspace\\JavaPrj\\test.txt"));
double prices;
int num;
StringBuffer name;
char chr;
int len;
try
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while(true)
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len=5;
name=new StringBuffer();
prices=in.readDouble();
in.readChar();
num=in.readInt();
in.readChar();
while((chr=in.readChar())!='\n')
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name.append(chr);
}
//double类型转String类型以及加入空格对齐的方法
System.out.println("产品名称："+name+"\t价格："+prices+getBlanks(len-Double.toString(prices).length())+"\t数量："+num);
}
}
catch (IOException e)
{undefined
// TODO Auto-generated catch block
e.printStackTrace();
}
}
catch (FileNotFoundException e)
{undefined
// TODO Auto-generated catch block
e.printStackTrace();
}
}
//加入空格进行对齐操作
public static String getBlanks(int n)
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String str="";
while(n>0)
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str+=" ";
n--;
}
return str;
}
}
