我看论坛里有两个人写了在iBatis中加入c3p0连接池，我也就不跟着掺合了，做这个ibatis下加入c3p0连接池的方法的原因是没法用spring，又需要连接池，且对DBCP一直观感不加，没法，只好自己动手加入c3p0连接池了。

在iBatis中加入c3p0连接池没啥难技术含量，写个文章备份下。

首先打开iBatis的源码包，找到com.ibatis.sqlmap.engine.datasource包，在里面新建个类，C3p0DataSourceFactory，并实现DataSourceFactory接口，里面的代码是Java代码
private DataSource dataSource;  
 
public DataSource getDataSource() {  
    return dataSource;  
}  
 
public void initialize(Map map) {  
    C3p0Configuration c3p0 = new C3p0Configuration(map);  
    dataSource = c3p0.getDataSource();  
} 

 private DataSource dataSource;
 
 public DataSource getDataSource() {
  return dataSource;
 }

 public void initialize(Map map) {
  C3p0Configuration c3p0 = new C3p0Configuration(map);
     dataSource = c3p0.getDataSource();
 }

在ibatis下加入c3p0连接池的下一步是到com.ibatis.common.jdbc包里，新建类C3p0Configuration，里面的代码是。。。太长了，原来在dbcp那部分里，还有单独加载配置文件的方法，我觉得如果连这个xml都读不了，那别的一样没法读。
Java代码
    private static final Probe PROBE = ProbeFactory.getProbe();  
    private DataSource dataSource;  
 
    /** 
     * Constructor to supply a map of properties 
     *  
     * @param properties 
     *            - the map of configuration properties 
     */ 
    public C3p0Configuration(Map properties) {  
        try {  
            dataSource = legacyC3p0Configuration(properties);  
        } catch (Exception e) {  
            throw new RuntimeException(  
                    "Error initializing C3p0DataSourceFactory.  Cause: " + e, e);  
        }  
    }  
 
    /** 
     * Getter for DataSource 
     *  
     * @return The DataSource 
     */ 
    public DataSource getDataSource() {  
        return dataSource;  
    }  
 
    private boolean notEmpty(String s) {  
        return s != null && s.length() > 0;  
    }  
 
    private boolean notSelfString(String s, String compareStr) {  
        return !s.equalsIgnoreCase(compareStr);  
    }  
 
    private DataSource legacyC3p0Configuration(Map map) {  
 
        ComboPooledDataSource combo = null;  
 
        try {  
            if (map.containsKey("JDBC.Driver")) {  
 
                combo = new ComboPooledDataSource();  
 
                String driverClass = (String) map.get("JDBC.Driver");  
                String jdbcUrl = (String) map.get("JDBC.ConnectionURL");  
                String user = (String) map.get("JDBC.Username");  
                String password = (String) map.get("JDBC.Password");  
 
                Class.forName(driverClass);  
                combo.setDriverClass(driverClass);  
                combo.setJdbcUrl(jdbcUrl);  
                combo.setUser(user);  
                combo.setPassword(password);  
 
                String acquireIncrement = (String) map  
                        .get("Pool.acquireIncrement");  
                if (notEmpty(acquireIncrement)  
                        && notSelfString(acquireIncrement, "acquireIncrement"))  
                    combo.setAcquireIncrement(Integer  
                            .parseInt(acquireIncrement));  
 
...................... 

 private static final Probe PROBE = ProbeFactory.getProbe();
 private DataSource dataSource;

 /**
  * Constructor to supply a map of properties
  *
  * @param properties
  *            - the map of configuration properties
  */
 public C3p0Configuration(Map properties) {
  try {
   dataSource = legacyC3p0Configuration(properties);
  } catch (Exception e) {
   throw new RuntimeException(
     "Error initializing C3p0DataSourceFactory.  Cause: " + e, e);
  }
 }

 /**
  * Getter for DataSource
  *
  * @return The DataSource
  */
 public DataSource getDataSource() {
  return dataSource;
 }

 private boolean notEmpty(String s) {
  return s != null && s.length() > 0;
 }

 private boolean notSelfString(String s, String compareStr) {
  return !s.equalsIgnoreCase(compareStr);
 }

 private DataSource legacyC3p0Configuration(Map map) {

  ComboPooledDataSource combo = null;

  try {
   if (map.containsKey("JDBC.Driver")) {

    combo = new ComboPooledDataSource();

    String driverClass = (String) map.get("JDBC.Driver");
    String jdbcUrl = (String) map.get("JDBC.ConnectionURL");
    String user = (String) map.get("JDBC.Username");
    String password = (String) map.get("JDBC.Password");

    Class.forName(driverClass);
    combo.setDriverClass(driverClass);
    combo.setJdbcUrl(jdbcUrl);
    combo.setUser(user);
    combo.setPassword(password);

    String acquireIncrement = (String) map
      .get("Pool.acquireIncrement");
    if (notEmpty(acquireIncrement)
      && notSelfString(acquireIncrement, "acquireIncrement"))
     combo.setAcquireIncrement(Integer
       .parseInt(acquireIncrement));

......................

***在com.ibatis.sqlmap.engine.config包里，找到SqlMapConfiguration，在里面找到，加上C3P0就可以实现在ibatis下加入c3p0连接池了
Java代码
// DATA SOURCE ALIASES  
typeHandlerFactory.putTypeAlias("SIMPLE", SimpleDataSourceFactory.class.getName());  
typeHandlerFactory.putTypeAlias("DBCP", DbcpDataSourceFactory.class.getName());  
typeHandlerFactory.putTypeAlias("C3P0", C3p0DataSourceFactory.class.getName());  
typeHandlerFactory.putTypeAlias("JNDI", JndiDataSourceFactory.class.getName());

通过这种手段，可以在ibatis下加入c3p0连接池，但是由于代码太长，在这里就不一一列出了，本文只是提出了一个在ibatis下加入c3p0连接池的思路，具体关于ibatis下加入c3p0连接池代码还需要朋友们自己斟酌。

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