AJ-542: add symbol connection pool

Author: lucaijun

src/com/xxdb/SimpleDBConnectionPool.java

@@ -1,5 +1,6 @@
 package com.xxdb;
 
+import com.xxdb.data.BasicInt;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -96,9 +97,10 @@ protected class SimpleDBConnectionPoolImpl {
             try {
                 for (int i = 0; i < initialPoolSize; i++) {
                     PoolEntry poolEntry = new PoolEntry(useSSL, compress, usePython, String.format("DolphinDBConnection_%d", i + 1));
-                    if (!poolEntry.connect(hostName, port, userId, password, initialScript, enableHighAvailability, highAvailabilitySites, reconnect, loadBalance)){
+                    if (!poolEntry.connect(hostName, port, userId, password, initialScript, enableHighAvailability, highAvailabilitySites, reconnect, loadBalance)) {
                         log.error(String.format("Connection %s connect failure.", poolEntry.connectionName));
-                    };
+                    }
+                    ;
                     poolEntryArrayList.add(poolEntry);
                 }
                 poolEntries = new CopyOnWriteArrayList<>(poolEntryArrayList);
@@ -165,8 +167,17 @@ public boolean isIdle() {
         public void close() {
             if (isBusy())
                 log.error("Cannot release the connection,is running now.");
-            else
-                inUse.compareAndSet(true, false);
+            else {
+                try {
+                    BasicInt ret = (BasicInt) run("1+1", true);
+                    if (!ret.isNull() && (ret.getInt() == 2))
+                        inUse.compareAndSet(true, false);
+                    else
+                        log.error("Cannot release memory,release connection failure.");
+                } catch (Exception e) {
+                    log.error("Cannot release memory, because " + e.getMessage());
+                }
+            }
         }
 
         private void release() {

src/com/xxdb/SimpleDBConnectionPoolConfig.java

@@ -10,32 +10,11 @@ public class SimpleDBConnectionPoolConfig {
     private boolean compress = false;
     private boolean useSSL = false;
     private boolean usePython = false;
-    private boolean loadBalance;
+    private boolean loadBalance = false;
     private boolean enableHighAvailability = false;
     private String[] highAvailabilitySites = null;
 
-    public SimpleDBConnectionPoolConfig(String hostName, int port, String userId, String password, int initialPoolSize, String initialScript, boolean compress, boolean useSSL, boolean usePython, boolean loadBalance, boolean enableHighAvailability, String[] highAvailabilitySites) {
-        this.hostName = hostName;
-        this.port = port;
-        this.userId = userId;
-        this.password = password;
-        this.initialPoolSize = initialPoolSize;
-        this.initialScript = initialScript;
-        this.compress = compress;
-        this.useSSL = useSSL;
-        this.usePython = usePython;
-        this.loadBalance = loadBalance;
-        this.enableHighAvailability = enableHighAvailability;
-        this.highAvailabilitySites = highAvailabilitySites;
-    }
-
-    public SimpleDBConnectionPoolConfig(String hostName, int port, String userId, String password, int initialPoolSize, boolean loadBalance) {
-        this.hostName = hostName;
-        this.port = port;
-        this.userId = userId;
-        this.password = password;
-        this.initialPoolSize = initialPoolSize;
-        this.loadBalance = loadBalance;
+    public SimpleDBConnectionPoolConfig() {
     }
 
     public String getHostName() {