java虚拟机开始学习

chenzhuo@picooc.com · chenzhuo@picooc.com · commit 3387621d1bbb · 2018-11-28T22:54:49.000+08:00
diff --git a/.gitignore b/.gitignore
@@ -6,4 +6,4 @@
 /.project
 /.mvn
 mvnw
-mvnw.cmd
+mvnw.cmd
diff --git a/src/main/java/com/sun/DigestExample.java b/src/main/java/com/sun/DigestExample.java
@@ -1,4 +1,4 @@
-package com.sun.proxy;
+package com.sun;
 
 import org.apache.commons.codec.binary.Base64;
 import java.io.UnsupportedEncodingException;
diff --git a/src/main/java/com/sun/Memony.java b/src/main/java/com/sun/Memony.java
@@ -1,4 +1,4 @@
-package com.sun.proxy;
+package com.sun;
 
 /**
  * @ClassName Memony
diff --git a/src/main/java/com/sun/Test.java b/src/main/java/com/sun/Test.java
@@ -1,4 +1,4 @@
-package com.sun.proxy;
+package com.sun;
 
 import java.util.ArrayList;
 import java.util.List;
diff --git a/src/main/java/com/sun/ThreadRun.java b/src/main/java/com/sun/ThreadRun.java
@@ -1,4 +1,4 @@
-package com.sun.proxy;
+package com.sun;
 
 /**
  * @ClassName ThreadRun
diff --git a/src/main/java/com/sun/ThreadTest.java b/src/main/java/com/sun/ThreadTest.java
@@ -1,4 +1,4 @@
-package com.sun.proxy;
+package com.sun;
 
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
diff --git a/src/main/java/com/sun/jvm/ClassLocader/VmClassLoader.java b/src/main/java/com/sun/jvm/ClassLocader/VmClassLoader.java
@@ -0,0 +1,52 @@
+package com.sun.jvm.ClassLocader;
+
+import com.basics.ClassLoaderTest.ClassLoaderLoadClass;
+
+/**
+ * @ClassName VmClassLoader
+ * @Despacito TODO 学习jvm
+ * @Author chenzhuo
+ * @Version 1.0
+ **/
+public class VmClassLoader {
+    /**
+     * 实例化在上
+     * private static Singer singer = new Singer();
+     * public static int count1 ;
+     * public static int count2 =0;
+     * count1:1
+     * count2:0
+     * <p>
+     * <p>
+     * public static int count1;
+     * public static int count2 = 0;
+     * private static Singer singer = new Singer();
+     * count1:1
+     * count2:1
+     * @param args
+     */
+    public static void main(String[] args) {
+      /*  ClassLoader classLoader = ClassLoader.getSystemClassLoader();
+        classLoader.loadClass();*/
+        Singer singer = Singer.getInstance();
+        System.out.println("count1:" + singer.count1);
+        System.out.println("count2:" + singer.count2);
+    }
+
+}
+
+class Singer {
+    public static int count1;
+    public static int count2 = 0;
+    private static Singer singer = new Singer();
+    public Singer() {
+        count1++;
+        count2++;
+    }
+
+    public static Singer getInstance() {
+        return singer;
+    }
+
+
+}
diff --git a/src/main/java/com/sun/jvm/ClassLocader/package-info.java b/src/main/java/com/sun/jvm/ClassLocader/package-info.java
@@ -0,0 +1,35 @@
+/**
+ * ClassLoader
+ * 有大概3个阶段
+ * 1.加载解析生成 生成到硬盘
+ *      这里调用的是javac的指令,
+ *      a.查询并且生成类的二进制数据 就是生成.class文件的字节码
+ * 2.连接
+ *     a.验证
+ *         1.验证生成的.class文件是否正确(文件头,魔数)
+ *         2.验证jvm版本 是否合理
+ *     b.准备
+ *          1.给类的静态变量初始化值
+ *              eg:
+ *                  public class A{
+ *                      private static int i = 3;
+ *                  }
+ *               这里会先给int i分配内存 并且 赋值为 0
+ *     c.解析
+ *         1.把类中的符号引用变成直接引用(????)
+ *
+ * 3.初始化
+ *     a.给静态变量赋值正确的值 如上eg,会直接赋值为3
+ *
+ * 4.初始化
+ *     a.主动使用
+ *      java虚拟机的只有在主动使用的时候才会主动初始化
+ *         1.new
+ *         2.读写变量
+ *         3.调用类的静态方法
+ *         4.Class.forName
+ *         5.初始化子类
+ *         6.标注为启动类的类
+ *     b.被动使用
+ */
+package com.sun.jvm.ClassLocader;
diff --git a/src/main/java/com/sun/jvm/package-info.java b/src/main/java/com/sun/jvm/package-info.java
@@ -0,0 +1,4 @@
+/**
+ *  关于虚拟机的学习
+ */
+package com.sun.jvm;

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-package com.sun.proxy;`
	`1`	`+package com.sun;`
`2`	`2`
`3`	`3`	`import org.apache.commons.codec.binary.Base64;`
`4`	`4`	`import java.io.UnsupportedEncodingException;`
-Original file line number
+Diff line change
@@ @@ -0,0 +1,4 @@ @@
 +/**
 + *  关于虚拟机的学习
 + */
 +package com.sun.jvm;