新增：RandomAccessFile的使用案例

Author: JeffLi1993

src/org/javacore/io/UsingRandomAccessFile.java

@@ -0,0 +1,58 @@
+package org.javacore.io;
+
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+
+/*
+ * Copyright [2015] [Jeff Lee]
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * @author Jeff Lee
+ * @since 2015-9-28 18:50:22
+ * RandomAccessFile的使用案例
+ */
+public class UsingRandomAccessFile {
+	// 文件名
+	static String file = "rtest.bat";
+	
+	static void display() throws IOException {
+		// 创建随机访问类，只读模式
+		RandomAccessFile rf = new RandomAccessFile(file, "r");
+		for (int i = 0; i < 7; i++)
+			System.out.println("Value "  + i + ": " + rf.readDouble());// 读取一个Double
+		System.out.println(rf.readUTF());// 读取一个字符串
+		rf.close();
+	}
+	
+	public static void main(String[] args) throws IOException {
+		// 创建随机访问类，读写模式
+		RandomAccessFile rf = new RandomAccessFile(file, "rw");
+		for (int i = 0; i < 7; i++)
+			rf.writeDouble( i * 1.123);// 写入一个Double
+		rf.writeUTF("文件结束");// 写入一个字符串
+		rf.close();
+		
+		display();
+		
+		rf = new RandomAccessFile(file, "rw");
+		rf.seek(5 * 8);// 设置文件指针偏移量
+		rf.writeDouble(47.003);
+		rf.close();
+		
+		display();
+	}
+}