上传文件

Author: lupingchn

java-knowledge-base/src/main/java/base/io/bio/BIOClient.java

@@ -0,0 +1,84 @@
+package base.io.bio;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.PrintWriter;
+import java.net.Socket;
+import java.util.Random;
+
+/**
+ * @author zhangluping on 2018/8/22.
+ */
+public class BIOClient {
+    /**
+     * 默认的端口号
+     */
+    private static int DEFAULT_SERVER_PORT = 12345;
+    private static String DEFAULT_SERVER_IP = "127.0.0.1";
+
+    public static void send(String expression) {
+        send(DEFAULT_SERVER_PORT, expression);
+    }
+
+    public static void send(int port, String expression) {
+        System.out.println("算术表达式为：" + expression);
+        Socket socket = null;
+        BufferedReader in = null;
+        PrintWriter out = null;
+        try {
+            socket = new Socket(DEFAULT_SERVER_IP, port);
+            in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
+            out = new PrintWriter(socket.getOutputStream(), true);
+            out.println(expression);
+            System.out.println("___结果为：" + in.readLine());
+        } catch (Exception e) {
+            e.printStackTrace();
+        } finally {
+            //一下必要的清理工作
+            if (in != null) {
+                try {
+                    in.close();
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+                in = null;
+            }
+            if (out != null) {
+                out.close();
+                out = null;
+            }
+            if (socket != null) {
+                try {
+                    socket.close();
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+                socket = null;
+            }
+        }
+    }
+
+    //测试主方法
+    public static void main(String[] args) throws InterruptedException {
+        //运行客户端
+        new Thread(new Runnable() {
+            @SuppressWarnings("static-access")
+            @Override
+            public void run() {
+                while(true){
+                    char operators[] = {'+','-','*','/'};
+                    Random random = new Random(System.currentTimeMillis());
+                    //随机产生算术表达式
+                    String expression = random.nextInt(10)+""+operators[random.nextInt(4)]+(random.nextInt(10)+1);
+                    BIOClient.send(expression);
+                    try {
+                        Thread.currentThread().sleep(random.nextInt(1000));
+                    } catch (InterruptedException e) {
+                        e.printStackTrace();
+                    }
+                }
+            }
+        }).start();
+    }
+}

java-knowledge-base/src/main/java/base/io/bio/BIOServer.java

@@ -0,0 +1,76 @@
+package base.io.bio;
+
+import java.io.IOException;
+import java.net.ServerSocket;
+import java.net.Socket;
+
+/**
+ * @author zhangluping on 2018/8/22.
+ */
+public class BIOServer {
+    /**
+     * 默认的端口号
+     */
+    private static int DEFAULT_PORT = 12345;
+    /**
+     * 单例的ServerSocket
+     */
+    private static ServerSocket server;
+
+    /**
+     * 根据传入参数设置监听端口，如果没有参数调用以下方法并使用默认值
+     *
+     * @throws IOException
+     */
+    public static void start() throws IOException {
+        //使用默认值
+        start(DEFAULT_PORT);
+    }
+
+    /**
+     * 这个方法不会被大量并发访问，不太需要考虑效率，直接进行方法同步就行了
+     *
+     * @param port
+     * @throws IOException
+     */
+    public synchronized static void start(int port) throws IOException {
+        if (server != null) {
+            return;
+        }
+        try {
+            //通过构造函数创建ServerSocket
+            //如果端口合法且空闲，服务端就监听成功
+            server = new ServerSocket(port);
+            System.out.println("服务器已启动，端口号：" + port);
+            //通过无线循环监听客户端连接
+            //如果没有客户端接入，将阻塞在accept操作上。
+            while (true) {
+                Socket socket = server.accept();
+                //当有新的客户端接入时，会执行下面的代码
+                //然后创建一个新的线程处理这条Socket链路
+                new Thread(new BIOServerHandler(socket)).start();
+            }
+        } finally {
+            //一些必要的清理工作
+            if (server != null) {
+                System.out.println("服务器已关闭。");
+                server.close();
+                server = null;
+            }
+        }
+    }
+
+    public static void main(String[] args) throws InterruptedException {
+        //运行服务器
+        new Thread(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    BIOServer.start();
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+        }).start();
+    }
+}

java-knowledge-base/src/main/java/base/io/bio/BIOServerHandler.java

@@ -0,0 +1,74 @@
+package base.io.bio;
+
+import base.io.util.Calculator;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.PrintWriter;
+import java.net.Socket;
+
+/**
+ * 客户端线程
+ * 用于处理一个客户端的Socket链路
+ *
+ * @author zhangluping on 2018/8/22.
+ */
+public class BIOServerHandler implements Runnable {
+    private Socket socket;
+
+    public BIOServerHandler(Socket socket) {
+        this.socket = socket;
+    }
+
+    @Override
+    public void run() {
+        BufferedReader in = null;
+        PrintWriter out = null;
+        try {
+            in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
+            out = new PrintWriter(socket.getOutputStream(), true);
+            String expression;
+            String result;
+            while (true) {
+                //通过BufferedReader读取一行
+                //如果已经读到输入流尾部，返回null,退出循环
+                //如果得到非空值，就尝试计算结果并返回
+                if ((expression = in.readLine()) == null) {
+                    break;
+                }
+                System.out.println(Thread.currentThread().getName()+ "服务器收到消息：" + expression);
+                try {
+                    result = Calculator.cal(expression).toString();
+                } catch (Exception e) {
+                    result = "计算错误：" + e.getMessage();
+                }
+                out.println(result);
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+        } finally {
+            //一些必要的清理工作
+            if (in != null) {
+                try {
+                    in.close();
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+                in = null;
+            }
+            if (out != null) {
+                out.close();
+                out = null;
+            }
+            if (socket != null) {
+                try {
+                    socket.close();
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+                socket = null;
+            }
+        }
+    }
+}

java-knowledge-base/src/main/java/base/io/util/Calculator.java

@@ -0,0 +1,14 @@
+package base.io.util;
+
+import javax.script.ScriptEngine;
+import javax.script.ScriptEngineManager;
+import javax.script.ScriptException;
+
+
+public final class Calculator {
+    private final static ScriptEngine jse = new ScriptEngineManager().getEngineByName("JavaScript");
+
+    public static Object cal(String expression) throws ScriptException {
+        return jse.eval(expression);
+    }
+}