此类从OutputStreamWriter类继承， 该类用于编写字符流，此类具有多个构造函数来创建所需的对象。
| Sr.No. | Constructor & Remark |
|---|---|
| 1 |
FileWriter(File file) 给定一个File对象，此构造函数创建一个FileWriter对象。 |
| 2 |
FileWriter(File file，boolean append) 该构造函数在给File对象提供布尔值的情况下创建FileWriter对象，该布尔值指示是否追加写入的数据。 |
| 3 |
FileWriter(FileDescriptor fd) 此构造函数创建与给定文件描述符关联的FileWriter对象。 |
| 4 |
FileWriter(String fileName) 给定文件名，此构造函数创建一个FileWriter对象。 |
| 5 |
FileWriter(String fileName，boolean append ) 此构造函数创建一个FileWriter对象，该对象的文件名带有一个布尔值，指示是否要附加写入的数据。 |
拥有 FileWriter 对象后，便会出现一个帮助程序方法列表，可用于处理文件。
| Sr.No. | Method & Remark |
|---|---|
| 1 |
public void write (int c) throws IOException 写一个字符。 |
| 2 |
public void write (char [] c，int offset，int len) 从offset开始写入字符数组的一部分，长度为len。 |
| 3 |
public void write(String s，int offset，int len) 从offset开始并以len的长度写一部分String。 |
FileWriter示例
import java.io.*;
public class FileRead {
public static void main(String args[])throws IOException {
File file = new File("Hello1.txt");
</span><span class="com">//创建文件</span><span class="pln">
file</span><span class="pun">.</span><span class="pln">createNewFile</span><span class="pun">();</span><span class="pln">
</span><span class="com">//创建一个 FileWriter 对象</span><span class="pln">
</span><span class="typ">FileWriter</span><span class="pln"> writer </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">new</span><span class="pln"> </span><span class="typ">FileWriter</span><span class="pun">(</span><span class="pln">file</span><span class="pun">);</span><span class="pln">
</span><span class="com">//将内容写入文件</span><span class="pln">
writer</span><span class="pun">.</span><span class="pln">write</span><span class="pun">(</span><span class="str">"This\n is\n an\n example\n"</span><span class="pun">);</span><span class="pln">
writer</span><span class="pun">.</span><span class="pln">flush</span><span class="pun">();</span><span class="pln">
writer</span><span class="pun">.</span><span class="pln">close</span><span class="pun">();</span><span class="pln">
</span><span class="com">//创建一个 FileReader 对象</span><span class="pln">
</span><span class="typ">FileReader</span><span class="pln"> fr </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">new</span><span class="pln"> </span><span class="typ">FileReader</span><span class="pun">(</span><span class="pln">file</span><span class="pun">);</span><span class="pln">
</span><span class="kwd">char</span><span class="pln"> </span><span class="pun">[]</span><span class="pln"> a </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">new</span><span class="pln"> </span><span class="kwd">char</span><span class="pun">[</span><span class="lit">50</span><span class="pun">];</span><span class="pln">
fr</span><span class="pun">.</span><span class="pln">read</span><span class="pun">(</span><span class="pln">a</span><span class="pun">);</span><span class="pln"> </span><span class="com">//将内容读取到数组</span><span class="pln">
</span><span class="kwd">for</span><span class="pun">(</span><span class="kwd">char</span><span class="pln"> c </span><span class="pun">:</span><span class="pln"> a</span><span class="pun">)</span><span class="pln">
</span><span class="typ">System</span><span class="pun">.</span><span class="kwd">out</span><span class="pun">.</span><span class="kwd">print</span><span class="pun">(</span><span class="pln">c</span><span class="pun">);</span><span class="pln"> </span><span class="com">//一个一个地打印字符</span><span class="pln">
fr</span><span class="pun">.</span><span class="pln">close</span><span class="pun">();</span><span class="pln">
}
}
这将产生以下输出-
This is an example
