README.md

About

This project demonstrates how to use datasource-proxy from JNDI using Tomcat.

• If ProxyDataSource is configued as a JNDI resource and passed to the application as javax.sql.DataSource, then only container needs to know datasource-proxy.jar. Your application doesn't need a dependency to datsource-proxy.jar.

Setup

Setup uses Tomcat and HSQLDB.

1. Download hsqldb.jar and datasource-proxy.jar(1.3+) place them to ${CATALINA_HOME}/lib

2. Configure Tomcat

• ${CATALINA_HOME}/conf/server.xml

  <!--
    Define actual datasource `jdbc/global/myDS` using embedded hsqldb.
   -->
  <Resource name="jdbc/global/myDS" 
            auth="Container"
            type="javax.sql.DataSource"
            description="ds"
            driverClassName="org.hsqldb.jdbc.JDBCDriver"
            url="jdbc:hsqldb:mem:aname"
  />
  
  <!--
    * Define `ProxyDataSource` with `DataSourceQueryCountListener` and `SystemOutQueryLoggingListener`
   -->
  <Resource name="jdbc/global/myProxy" 
            auth="Container"
            type="net.ttddyy.dsproxy.support.ProxyDataSource"
            factory="net.ttddyy.dsproxy.support.jndi.ProxyDataSourceObjectFactory"
            description="ds"
            listeners="count,sysout"
            proxyName="DS-PROXY"
            format="json"
            dataSource="java:jdbc/global/myDS"
  />

• ${CATALINA_HOME}/conf/context.xml

  <!--
    Expose defined `ProxyDataSource` to application as a `DataSource`
   -->
  <ResourceLink name="jdbc/myDS"
                global="jdbc/global/myProxy"
                type="javax.sql.DataSource"
  />

1. build this application and deploy to tomcat

> mvn package
// or mvn war:war, etc

• copy war to ${CATALINA_HOME}/webapps, or symlink, etc

1. start tomcat and access the url

---

Sample Output

Application startup log:

{"name":"DS-PROXY", "time":1, "success":true, "type":"Statement", "batch":false, "querySize":1, "batchSize":0, "query":["CREATE TABLE users(id INT, name VARCHAR(255))"], "params":[]}
{"name":"DS-PROXY", "time":0, "success":true, "type":"Prepared", "batch":true, "querySize":1, "batchSize":3, "query":["INSERT INTO users (id, name) VALUES (?, ?)"], "params":[{"1":"1","2":"foo"},{"1":"2","2":"bar"},{"1":"3","2":"baz"}]}

Accessing application:

> curl http://localhost:8080/dsp-lookup/
  {"count":3}

Log:

{"name":"DS-PROXY", "time":6, "success":true, "type":"Statement", "batch":false, "querySize":1, "batchSize":0, "query":["SELECT COUNT(*) FROM users"], "params":[]}