装饰模式在Java I/O库中的应用
编写一个装饰者把所有的输入流内的大写字符转化成小写字符：
importjava.io.FilterInputStream;
importjava.io.IOException;
importjava.io.InputStream;
publicclassLowerCaseInputStreamextendsFilterInputStream
{
protectedLowerCaseInputStream(InputStreamin)
{
super(in);
}
@Override
publicintread()throwsIOException
{
intc=super.read();
return(c==-1?c:Character.toLowerCase((char)c));
}
@Override
publicintread(byte[]b,intoffset,intlen)throwsIOException
{
intresult=super.read(b,offset,len);
for(inti=offset;i<offset+result;i++)
{
b[i]=(byte)Character.toLowerCase((char)b[i]);
}
returnresult;
}
}
测试我们的装饰者类：
importjava.io.*;
publicclassInputTest
{
publicstaticvoidmain(String[]args)throwsIOException
{
intc;
try
{
InputStreamin=newLowerCaseInputStream(newBufferedInputStream(
newFileInputStream("D:\\test.txt")));
while((c=in.read())>=0)
{
System.out.print((char)c);
}
in.close();
}
catch(IOExceptione)
{
e.printStackTrace();
}
}
}