1 files changed, 234 insertions, 0 deletions
diff --git a/sandbox/rfeng/minicore/src/main/java/org/apache/tuscany/core/monitor/ProxyMonitorFactory.java b/sandbox/rfeng/minicore/src/main/java/org/apache/tuscany/core/monitor/ProxyMonitorFactory.java
new file mode 100644
index 0000000000..d9ca9e6cfc
--- /dev/null
+++ b/sandbox/rfeng/minicore/src/main/java/org/apache/tuscany/core/monitor/ProxyMonitorFactory.java
@@ -0,0 +1,234 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.    
+ */
+package org.apache.tuscany.core.monitor;
+
+import java.util.Map;
+import java.util.Properties;
+import java.util.HashMap;
+import java.util.ResourceBundle;
+import java.util.Locale;
+import java.util.MissingResourceException;
+import java.util.List;
+import java.util.ArrayList;
+import java.util.WeakHashMap;
+import java.util.logging.Level;
+import java.lang.ref.WeakReference;
+import java.lang.reflect.Method;
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Proxy;
+import java.io.PrintWriter;
+import java.io.StringWriter;
+
+import org.apache.tuscany.host.MonitorFactory;
+import org.apache.tuscany.host.monitor.FormatterRegistry;
+import org.apache.tuscany.host.monitor.ExceptionFormatter;
+import org.apache.tuscany.api.annotation.LogLevel;
+
+/**
+ * @version $Rev$ $Date$
+ */
+public abstract class ProxyMonitorFactory implements MonitorFactory, FormatterRegistry {
+    protected String bundleName;
+    protected final List<ExceptionFormatter> formatters = new ArrayList<ExceptionFormatter>();
+    protected final ExceptionFormatter defaultFormatter = new DefaultExceptionFormatter();
+    protected Level defaultLevel;
+    protected Map<String, Level> levels;
+    private final Map<Class<?>, WeakReference<?>> proxies = new WeakHashMap<Class<?>, WeakReference<?>>();
+
+    public void initialize(Map<String, Object> configProperties) {
+        if (configProperties == null) {
+            return;
+        }
+        initInternal(configProperties);
+    }
+
+    protected void initInternal(Map<String, Object> configProperties) {
+        try {
+            this.defaultLevel = (Level) configProperties.get("defaultLevel");
+            this.bundleName = (String) configProperties.get("bundleName");
+            Properties levels = (Properties) configProperties.get("levels");
+
+            this.levels = new HashMap<String, Level>();
+            if (levels != null) {
+                for (Map.Entry<Object, Object> entry : levels.entrySet()) {
+                    String method = (String) entry.getKey();
+                    String level = (String) entry.getValue();
+                    try {
+                        this.levels.put(method, Level.parse(level));
+                    } catch (IllegalArgumentException e) {
+                        throw new InvalidLevelException(method, level);
+                    }
+                }
+            }
+        } catch (ClassCastException cce) {
+            throw new IllegalArgumentException(cce.getLocalizedMessage());
+        }
+    }
+
+    public synchronized <T> T getMonitor(Class<T> monitorInterface) {
+        T proxy = getCachedMonitor(monitorInterface);
+        if (proxy == null) {
+            proxy = createMonitor(monitorInterface);
+            proxies.put(monitorInterface, new WeakReference<T>(proxy));
+        }
+        return proxy;
+    }
+
+    protected <T> T getCachedMonitor(Class<T> monitorInterface) {
+        WeakReference<?> ref = proxies.get(monitorInterface);
+        return (ref != null) ? monitorInterface.cast(ref.get()) : null;
+    }
+
+    protected <T> T createMonitor(Class<T> monitorInterface) {
+        String className = monitorInterface.getName();
+        Method[] methods = monitorInterface.getMethods();
+        Map<String, Level> levels = new HashMap<String, Level>(methods.length);
+        for (Method method : methods) {
+            String key = className + '#' + method.getName();
+            Level level = null;
+            if (this.levels != null) {
+                this.levels.get(key);
+            }
+            // if not specified the in config properties, look for an annotation on the method
+            if (level == null) {
+                LogLevel annotation = method.getAnnotation(LogLevel.class);
+                if (annotation != null && annotation.value() != null) {
+                    try {
+                        level = Level.parse(annotation.value());
+                    } catch (IllegalArgumentException e) {
+                        // bad value, just use the default
+                        level = defaultLevel;
+                    }
+                }
+            }
+            if (level == null) {
+                level = defaultLevel;
+            }
+            levels.put(method.getName(), level);
+        }
+
+        InvocationHandler handler = createInvocationHandler(monitorInterface, levels);
+        Object proxy = Proxy.newProxyInstance(monitorInterface.getClassLoader(),
+                                              new Class<?>[]{monitorInterface},
+                                              handler);
+        return monitorInterface.cast(proxy);
+    }
+
+    protected <T> ResourceBundle locateBundle(Class<T> monitorInterface, String bundleName) {
+        Locale locale = Locale.getDefault();
+        ClassLoader cl = monitorInterface.getClassLoader();
+        String packageName = monitorInterface.getPackage().getName();
+        while (true) {
+            try {
+                return ResourceBundle.getBundle(packageName + '.' + bundleName, locale, cl);
+            } catch (MissingResourceException e) {
+                //ok
+            }
+            int index = packageName.lastIndexOf('.');
+            if (index == -1) {
+                break;
+            }
+            packageName = packageName.substring(0, index);
+        }
+        try {
+            return ResourceBundle.getBundle(bundleName, locale, cl);
+        } catch (Exception e) {
+            return null;
+        }
+    }
+
+    public void register(ExceptionFormatter formatter) {
+        formatters.add(formatter);
+    }
+
+    public void unregister(ExceptionFormatter formatter) {
+        formatters.remove(formatter);
+    }
+
+    protected abstract <T> InvocationHandler createInvocationHandler(Class<T> monitorInterface,
+                                                                 Map<String, Level> levels);
+
+    protected String formatException(Throwable e) {
+        ExceptionFormatter formatter = defaultFormatter;
+        for (ExceptionFormatter candidate : formatters) {
+            if (candidate.canFormat(e.getClass())) {
+                formatter = candidate;
+                break;
+            }
+        }
+        StringWriter writer = new StringWriter();
+        PrintWriter pw = new PrintWriter(writer);
+        formatter.write(pw, e);
+        format(pw, e);
+        pw.close();
+        return writer.toString();
+    }
+
+    protected void format(PrintWriter writer, Throwable throwable) {
+        writer.println(throwable.getClass().getName());
+        StackTraceElement[] trace = throwable.getStackTrace();
+        for (StackTraceElement aTrace : trace) {
+            writer.println("\tat " + aTrace);
+        }
+        Throwable ourCause = throwable.getCause();
+
+        if (ourCause != null) {
+            printStackTraceAsCause(writer, ourCause, trace);
+        }
+    }
+
+    protected void printStackTraceAsCause(PrintWriter pw,
+                                        Throwable throwable,
+                                        StackTraceElement[] causedTrace) {
+
+        // Compute number of frames in common between this and caused
+        StackTraceElement[] trace = throwable.getStackTrace();
+        int m = trace.length - 1;
+        int n = causedTrace.length - 1;
+        while (m >= 0 && n >= 0 && trace[m].equals(causedTrace[n])) {
+            m--;
+            n--;
+        }
+        int framesInCommon = trace.length - 1 - m;
+
+        pw.println("Caused by: " + throwable.getClass().getName());
+
+        ExceptionFormatter formatter = defaultFormatter;
+        for (ExceptionFormatter candidate : formatters) {
+            if (candidate.canFormat(throwable.getClass())) {
+                formatter = candidate;
+                break;
+            }
+        }
+        formatter.write(pw, throwable);
+
+        for (int i = 0; i <= m; i++) {
+            pw.println("\tat " + trace[i]);
+        }
+        if (framesInCommon != 0) {
+            pw.println("\t... " + framesInCommon + " more");
+        }
+
+        // Recurse if we have a cause
+        Throwable ourCause = throwable.getCause();
+        if (ourCause != null) {
+            printStackTraceAsCause(pw, ourCause, trace);
+        }
+    }
+}