fix：优化代码，实现一个可用的classLoader

README.md

@@ -2,4 +2,15 @@
 
 特定驱动的ClassLoader拦截器demo
 
-05-20：demo需要依赖最新release分支的datasource模块
+使用方法：
+
+ 该插件是用于隔离数据库JDBC的驱动jar包，从而避免驱动jar引入的jar包冲突问题
+ 
+ 启用该插件以后，需要在WEB-INF目录下新建一个driverlib文件夹，将对应的驱动jar包放入这个文件夹内即可
+ 
+ 注意：使用了隔离插件以后驱动jar包不需要放在lib目录下
+ 
+ 目前该插件默认是隔离MySQL的驱动，如果是其他数据源，只需要修改DRIVER_NAME_KEY为对应的驱动即可
+
+PS：demo需要依赖最新release分支的datasource模块
+

plugin.xml

@@ -10,6 +10,7 @@
     <change-notes><![CDATA[
       [2019-05-16]初始化。<br/>
       [2019-05-20]优化逻辑。<br/>
+      [2019-05-30]实现一个可用的ClassLoader。<br/>
     ]]></change-notes>
     <main-package>com.fr.plugin.dialect.classloader</main-package>
     <extra-core>

src/main/java/com/fr/plugin/dialect/classloader/ClassLoaderHandler.java

@@ -3,26 +3,36 @@ package com.fr.plugin.dialect.classloader;
 
 import com.fr.intelli.record.Focus;
 import com.fr.intelli.record.Original;
+import com.fr.io.utils.ResourceIOUtils;
 import com.fr.log.FineLoggerFactory;
 import com.fr.record.analyzer.EnableMetrics;
 import com.fr.stable.fun.impl.AbstractDataSourceDriverLoader;
 
+import java.io.File;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.ArrayList;
+import java.util.List;
+
 /**
  * Created by Munin on 2019/5/20
  */
 
 @EnableMetrics
 public class ClassLoaderHandler extends AbstractDataSourceDriverLoader {
+    //插件获取jar的路径，和lib同级的driverlib目录
+    public static final String DRIVER_LIB_DIR = "driverlib";
 
     //demo设置为mysql为目标驱动
-    private static final String MYSQL_KEY = "com.mysql.jdbc.Driver";
+    private static final String DRIVER_NAME_KEY = "com.mysql.jdbc.Driver";
 
     @Focus(id = "com.fr.plugin.dialect.classloader.ClassLoaderHandler", text = "", source = Original.PLUGIN)
     public boolean isInterceptAllowed(String driverName) {
         if (driverName == null) {
             FineLoggerFactory.getLogger().error("error driver name");
+            return false;
         }
-        if (driverName.compareTo(MYSQL_KEY) == 0) {
+        if (driverName.equals(DRIVER_NAME_KEY)) {
             FineLoggerFactory.getLogger().info("correct driver name");
             return true;
         }
@@ -32,7 +42,33 @@ public class ClassLoaderHandler extends AbstractDataSourceDriverLoader {
     @Focus(id = "com.fr.plugin.dialect.classloader.ClassLoaderHandler", text = "", source = Original.PLUGIN)
     public ClassLoader getClassLoader() {
         FineLoggerFactory.getLogger().info("====== Loading Mysql ClassLoader ... ======");
-        //具体实现可以自定义，这里就直接返回一个null
+        URL[] urls = getJarURLS();
-        return null;
+        ClassLoader cl = new DriverClassLoader(urls);
+        Thread.currentThread().setContextClassLoader(cl);
+        return cl;
+    }
+
+
+    public URL[] getJarURLS() {
+        List<URL> libUrls = new ArrayList<URL>();
+        try {
+
+            String dir = ResourceIOUtils.getRealPath(DRIVER_LIB_DIR);
+            File parentDir = new File(dir);
+            File[] files = parentDir.listFiles();
+            if (files != null) {
+                for (File file : files) {
+                    try {
+                        libUrls.add(file.toURI().toURL());
+                    } catch (MalformedURLException e) {
+                        FineLoggerFactory.getLogger().warn("get JAR URLS error, the driver lib path is:{}", dir);
+                    }
+
+                }
+            }
+        } catch (Exception e) {
+        }
+
+        return libUrls.toArray(new URL[0]);
     }
 }

src/main/java/com/fr/plugin/dialect/classloader/DriverClassLoader.java

@@ -0,0 +1,58 @@
+package com.fr.plugin.dialect.classloader;
+
+import com.fr.log.FineLoggerFactory;
+
+import java.net.URL;
+import java.net.URLClassLoader;
+
+/**
+ * @author: Roy
+ * @date: 2019/5/29 6:39 PM
+ */
+public class DriverClassLoader extends URLClassLoader {
+
+    public DriverClassLoader(URL[] urls) {
+        super(urls, Thread.currentThread().getContextClassLoader());
+    }
+
+
+    @Override
+    public Class<?> loadClass(String name) throws ClassNotFoundException {
+        synchronized (getClassLoadingLock(name)) {
+            Class<?> c = findLoadedClass(name);
+            if (c == null) {
+                try {
+                    c = findClass(name);
+                    FineLoggerFactory.getLogger().debug("load class {} from driverlib successful", name);
+                } catch (Exception e) {
+                    //can not find class in isolate dir, try to load from common lib
+                }
+            }
+
+            if (c == null) {
+                FineLoggerFactory.getLogger().debug("Did not find class{}, in the paths {}, try to get from common lib", name, this.getUrlStrings());
+                c = super.loadClass(name);
+            }
+
+            return c;
+        }
+
+    }
+
+    private String getUrlStrings() {
+        StringBuilder stringBuilder = new StringBuilder();
+        try {
+
+            for (URL url : getURLs()) {
+                stringBuilder
+                        .append("\n\r")
+                        .append(url.getPath())
+                        .append("\n\r");
+            }
+
+        } catch (Exception e) {
+
+        }
+        return stringBuilder.toString();
+    }
+}