怎么使用InputStreamReader
网上介绍：重要的类是InputStreamReader，它是字节转换为字符的桥梁字节流是什么， 字符流是什么，字节转换为字符不是用char() 强制转换就可以了，为什么要引进这个类呢？
下面这个程序用字节流处理，也能处理文件
java StreamRecoderUTF-8 UTF-8 D:\\kk.txt D:\\kk2.txt
package
import java.io.*;
public class StreamRecoder {
public static void main(String[] args) {
if (args.length < 2) {
System.err.println(
"Usage: java StreamRecoder "
+ "infile_encoding outfile_encoding infile outfile");
return;
}
InputStreamReader isr = null;
OutputStreamWriter osw = null;
try {
File infile = new File(args);
File outfile = new File(args);
if (outfile.exists( )
&& infile.getCanonicalPath().equals(outfile.getCanonicalPath( ))) {
System.err.println("Can't convert file in place");
return;
}
FileInputStream fin = new FileInputStream(infile);
FileOutputStream fout = new FileOutputStream(outfile);
// isr = new InputStreamReader(fin, args);
// osw = new OutputStreamWriter(fout, args);
while (true) {
int c = fin.read( );
if (c == -1) break;// end of stream
fout.write(c);
}
fout.close( );
fin.close( );
}
catch (IOException ex) {
System.err.println(ex);
ex.printStackTrace( );
}
finally {
if (isr != null) {
try {
isr.close( );
} catch (IOException ex) {
ex.printStackTrace( );
}
}
if (osw != null) {
try {
osw.close( );
}
catch (IOException ex) {
ex.printStackTrace( );
}
}
}
}
}
我如果改成这样，用字符流来处理， 如果kk.txt是中文， 就会出现乱码，
那用字符流处理还有什么用呢
import java.io.*;
public class StreamRecoder {
public static void main(String[] args) {
if (args.length < 2) {
System.err.println(
"Usage: java StreamRecoder "
+ "infile_encoding outfile_encoding infile outfile");
return;
}
InputStreamReader isr = null;
OutputStreamWriter osw = null;
try {
File infile = new File(args);
File outfile = new File(args);
if (outfile.exists( )
&& infile.getCanonicalPath().equals(outfile.getCanonicalPath( ))) {
System.err.println("Can't convert file in place");
return;
}
FileInputStream fin = new FileInputStream(infile);
FileOutputStream fout = new FileOutputStream(outfile);
isr = new InputStreamReader(fin, args);
osw = new OutputStreamWriter(fout, args);
while (true) {
int c = isr.read( );
if (c == -1) break;// end of stream
osw.write(c);
}
osw.close( );
isr.close( );
}
catch (IOException ex) {
System.err.println(ex);
ex.printStackTrace( );
}
finally {
if (isr != null) {
try {
isr.close( );
} catch (IOException ex) {
ex.printStackTrace( );
}
}
if (osw != null) {
try {
osw.close( );
}
catch (IOException ex) {
ex.printStackTrace( );
}
}
}
}
}
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