Java IO讀檔案和寫檔案

寫檔案Java代碼：

package hand.wang.test;</p><p>import java.io.*;</p><p>public class write {<br /> public static void main(String[] args) {<br /> write("E://123.txt", "hello");<br /> }</p><p> public static void write(String path, String content) {<br /> String s = new String();<br /> String s1 = new String();</p><p> try {<br /> File f = new File(path);</p><p> if (f.exists()) {<br /> System.out.println("檔案存在");<br /> } else {<br /> System.out.println("檔案不存在，正在建立...");<br /> if (f.createNewFile()) {<br /> System.out.println("檔案建立成功！");<br /> } else {<br /> System.out.println("檔案建立失敗！");<br /> }<br /> }</p><p> BufferedReader input = new BufferedReader(new FileReader(f));</p><p> while ((s = input.readLine()) != null) {<br /> s1 += s + "/n";<br /> }</p><p> System.out.println("檔案內容：" + s1);<br /> input.close();<br /> s1 += content;<br /> BufferedWriter output = new BufferedWriter(new FileWriter(f));<br /> output.write(s1);<br /> output.close();<br /> } catch (Exception e) {<br /> e.printStackTrace();<br /> }<br /> }<br />}

 

讀檔案Java代碼：

package hand.wang.test;</p><p>import java.io.BufferedReader;<br />import java.io.File;<br />import java.io.FileInputStream;<br />import java.io.FileNotFoundException;<br />import java.io.InputStreamReader;</p><p>public class Read {<br /> public static void main(String[] args) {<br /> read("E://123.txt");<br /> }</p><p> public static void read(String file) {<br /> String s = null;<br /> StringBuffer sb = new StringBuffer();<br /> File f = new File(file);<br /> if (f.exists()) {<br /> try {<br /> BufferedReader br =<br /> new BufferedReader(new InputStreamReader(new FileInputStream(f)));<br /> while ((s = br.readLine()) != null) {<br /> sb.append(s);<br /> }<br /> System.out.println(sb);<br /> } catch (Exception e) {<br /> e.printStackTrace();<br /> }<br /> } else {<br /> System.out.println("檔案不存在!");<br /> }<br /> }<br />}