Java-流的简单使用：读取文件、写入文件（面试题：删除注释代码）

摘要：前天面试Android时遇到机试，题目是删除注释中的代码。机试开始时不能上网，我恰好忘了读写字符流的相关代码API，幸好后来能上网查关于流的API，最终得以把程序写出来。

题目：请编程将Example.c文件中的所有注释删除，将结果写入Example.i文件中。

输入用例Example.c：

struct a {
char a /*2392839238923 /*kasdlfjasld*/;
char b; //23232392839
};
/*
askdashfla'
asdfalskdfhlksafdhla
fasdjfhalsdjfhlasdf
askjdfhlkajds
* /
*/
void Function(int param /*232323* / */)
{
//*2323234234l
int i = 1;//2923939
char str[] = "/*232323";
int j = 0;
i = i / j * i;
strcpy(str, "/*lakjslkdflksd*/");
}

我编写的程序：

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class Test {
public static void main(String args[])
{
String InputPath="../Example_1.c";
String OutputPath="../Example_1.i";

String Data=LoadFile(InputPath);
Data=Handle(Data);

WriteFile(Data,OutputPath);
}

//把文件中的数据转化为字符串

private static String LoadFile(String path)
{
File file = new File(path);
BufferedReader reader=null;
String temp;
String result="";

try {
reader =new BufferedReader(new FileReader(file));

while((temp=reader.readLine())!=null)
{
result=result+temp+"\r\n";
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(result);
return result;
}

//把数据写进文件
private static void WriteFile(String data,String path)
{
try {
FileWriter fw=new FileWriter(path);
BufferedWriter bw=new BufferedWriter(fw);

bw.write(data);

bw.close();
fw.close();

} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return;
}

//删掉注释的方法
private static String Handle(String data)
{
StringBuffer sb= new StringBuffer();
int posStar = 0,posEnd=0,i=0;
while(i<data.length())
{
System.out.print(data.charAt(i));
if(data.charAt(i)=='"')
{
do
{
sb.append(data.charAt(i));
i++;
}while(data.charAt(i)!='"');
sb.append(data.charAt(i));
i++;
continue;
}
else if(data.charAt(i)=='/')
{
if(data.charAt(i+1)=='/')
{
do
{
i++;
}while(data.charAt(i)!='\r');
sb.append(data.charAt(i));
i++;
continue;
}

else if(data.charAt(i+1)=='*')
{

do
{
i++;
}while(data.charAt(i)!='*'||((data.charAt(i)=='*')&&(data.charAt(i-1)=='/')));
do
{
i++;
}while(data.charAt(i)!='/');

i++;
posStar=i;
continue;
}
}
else if(data.charAt(i)=='*')
{
if(data.charAt(i+1)=='/')
{

posEnd=i;
i=i+2;
System.out.println(posStar+" "+posEnd+" "+sb.length());
sb.delete(sb.length()-(posEnd-posStar), sb.length());
continue;
}
else
{
while(data.charAt(i+1)==' ')
{
sb.append(data.charAt(i));
i++;

}
if(data.charAt(i+1)=='/')
{
posEnd=i;
i=i+2;
sb.delete(sb.length()-(posEnd-posStar), sb.length());
continue;
}
else{
continue;
}
}
}
sb.append(data.charAt(i));
i++;
}
return new String(sb);
}

}

输出结果：

struct a {
char a ;
char b;
};

void Function(int param )
{

int i = 1;
char str[] = "/*232323";
int j = 0;
i = i / j * i;
strcpy(str, "/*lakjslkdflksd*/");
}

还有更好的答案吗？望共同探讨。