两个不同的 Velocity Engine 实例，使用不同的配置

VelocityEngineTest.java

import java.io.StringWriter;  import java.io.Writer;  import java.util.Properties;    import org.apache.velocity.Template;  import org.apache.velocity.VelocityContext;  import org.apache.velocity.app.VelocityEngine;    public class VelocityEngineTest {      private static final String TEMPLATE_NAME = "VelocityEngineTest.vm";      public static void main(String[] args) throws Exception {      Properties p1 = new Properties();      p1.put("resource.loader", "file");      p1.put("file.resource.loader.class",          "org.apache.velocity.runtime.resource.loader.FileResourceLoader");      p1.put("file.resource.loader.path", "./src/ve1");        Properties p2 = new Properties();      p2.put("resource.loader", "file");      p2.put("file.resource.loader.class",          "org.apache.velocity.runtime.resource.loader.FileResourceLoader");      p2.put("file.resource.loader.path", "./src/ve2");        //now create the engines      VelocityEngine ve1 = new VelocityEngine();      ve1.init(p1);        VelocityEngine ve2 = new VelocityEngine();      ve2.init(p2);        // now get the output for each engine      writeTemplateOutput(ve1);      writeTemplateOutput(ve2);      }      public static void writeTemplateOutput(VelocityEngine ve) throws Exception {      Template t = ve.getTemplate(TEMPLATE_NAME);        Writer writer = new StringWriter();      t.merge(new VelocityContext(), writer);        System.out.println(writer.toString());    }  }