appendcaar这样用对吗？

Question

use stfDir.append(ch1) and stfFilename.append(ch2)

Answer 1

stfDir.append(ch1);
String没有appendchar的方法。

Answer 2

下面这个程序是书上的例子
/ReadFromFile.java
import java.io.*;
class ReadFromFile
{
public static void main(String args[])
{
           System.out.println("Please enter a directory that the file located in:"); StringBuffer stfDir = new StringBuffer();
char ch1;
         char ch2;
while((ch1 = (char)System.in.read())!='\n')
         {
           stfDir.appendchar(ch1);
}
File dir = new File(stfDir.toString()); System.out.println("Please enter a filename that want to read:");
         StringBuffer stfFilename = new StringBuffer();
while((ch2 = (char)System.in.read())!='\n')
{
stfFilename.append(ch2);
}
      File readFrom = new File(dir,stfFilename.toString());
      if(readFrom.isFile() && readFrom.canWrite() && readFrom.canRead())
     {
     RandomAccessFile rafFile =new RandomAccessFile(readFrom,"rw");
    while(rafFile.getFilePointer()<rafFile.length())
     System.out.println(rafFile.readLine());
     rafFile.close();
}
else

       System.out.println("File cann't be read!");
}
}运行JAVAC  ReadFromFile.java
系统显示stfDir.appendchar(ch1)有错。请问怎么修改？谢谢

Answer 3

什么书，这么垃圾，上面不是告诉你怎么改了么？import java.io.*;
class ReadFromFile
{
public static void main(String args[])
{
           System.out.println("Please enter a directory that the file located in:"); StringBuffer stfDir = new StringBuffer();
char ch1;
         char ch2;
while((ch1 = (char)System.in.read())!='\n')
         {
           stfDir.append(ch1);
}
File dir = new File(stfDir.toString()); System.out.println("Please enter a filename that want to read:");
         StringBuffer stfFilename = new StringBuffer();
while((ch2 = (char)System.in.read())!='\n')
{
stfFilename.append(ch2);
}
      File readFrom = new File(dir,stfFilename.toString());
      if(readFrom.isFile() && readFrom.canWrite() && readFrom.canRead())
     {
     RandomAccessFile rafFile =new RandomAccessFile(readFrom,"rw");
    while(rafFile.getFilePointer()<rafFile.length())
     System.out.println(rafFile.readLine());
     rafFile.close();
}
else

       System.out.println("File cann't be read!");
}
}

Answer 4

bluesmile979(笑着) 你好：
  感谢您多次的帮助。我刚才把上面这段程序运行了一遍。系统仍然显示以下错误：
      while((ch2 = (char)System.in.read())!='\n')
                                    ^
ReadFromFile.java:24: unreported exception java.io.FileNotFoundException; must b
e caught or declared to be thrown
     RandomAccessFile rafFile =new RandomAccessFile(readFrom,"rw");
                               ^
ReadFromFile.java:25: unreported exception java.io.IOException; must be caught o
r declared to be thrown
    while(rafFile.getFilePointer()<rafFile.length())
                 ^
ReadFromFile.java:25: unreported exception java.io.IOException; must be caught o
r declared to be thrown
    while(rafFile.getFilePointer()<rafFile.length())
                                          ^
ReadFromFile.java:26: unreported exception java.io.IOException; must be caught o
r declared to be thrown
     System.out.println(rafFile.readLine());
                               ^
ReadFromFile.java:27: unreported exception java.io.IOException; must be caught o
r declared to be thrown
     rafFile.close();
            ^
7 errors

Answer 5

import java.io.*;
class ReadFromFile
{
public static void main(String args[])
{
           System.out.println("Please enter a directory that the file located in:"); StringBuffer stfDir = new StringBuffer();
try{
char ch1;
         char ch2;
while((ch1 = (char)System.in.read())!='\n')
         {
           stfDir.append(ch1);
}
File dir = new File(stfDir.toString()); System.out.println("Please enter a filename that want to read:");
         StringBuffer stfFilename = new StringBuffer();
while((ch2 = (char)System.in.read())!='\n')
{
stfFilename.append(ch2);
}
      File readFrom = new File(dir,stfFilename.toString());
      if(readFrom.isFile() && readFrom.canWrite() && readFrom.canRead())
     {
     RandomAccessFile rafFile =new RandomAccessFile(readFrom,"rw");
    while(rafFile.getFilePointer()<rafFile.length())
     System.out.println(rafFile.readLine());
     rafFile.close();
}
else

       System.out.println("File cann't be read!");
}catch(Exception e){
}
}
}