前言

一定要多看官方文档，网上找的都是东抄西抄，而且写的很皮毛
http://juel.sourceforge.net/guide/start.html

依赖

  1. <dependency>
  2.   <groupId>javax.el</groupId>
  3.   <artifactId>javax.el-api</artifactId>
  4.    <version>3.0.0</version>
  5. </dependency>
  6. <!-- juel  -->
  7. <dependency>
  8.   <groupId>de.odysseus.juel</groupId>
  9.   <artifactId>juel-api</artifactId>
  10.   <version>2.2.7</version>
  11. </dependency>
  12. <dependency>
  13.   <groupId>de.odysseus.juel</groupId>
  14.   <artifactId>juel-impl</artifactId>
  15.   <version>2.2.7</version>
  16. </dependency>
  17. <dependency>
  18.   <groupId>de.odysseus.juel</groupId>
  19.   <artifactId>juel-spi</artifactId>
  20.   <version>2.2.7</version>
  21. </dependency>

常见用法

  1. @Test
  2. public void testGetStarted() {
  3.     //step1
  4.     ExpressionFactory factory = new ExpressionFactoryImpl();
  5.     SimpleContext context = new SimpleContext();
  7.     //step2
  8.     context.setVariable("var1", factory.createValueExpression("Hello", String.class));
  9.     context.setVariable("var2", factory.createValueExpression("World", String.class));
  11.     //step3
  12.     String s = "{\"argIn1\":\"${var1}\",\"argIn2\":\"${var2}\"}";
  13.     ValueExpression e = factory.createValueExpression(context, s, String.class);
  14.     System.out.println(e.getValue(context));// --> {"argIn1":"Hello","argIn2":"World"}
  15.     }
  1. @Test
  2. public void testResolveBean() {
  4.     // 启用对象的方法调用
  5.     // 启用NULL属性
  6.     // 启用忽略类型不一致产生的异常
  7.     Properties properties = new Properties();
  8.     properties.setProperty(ExpressionFactoryImpl.PROP_METHOD_INVOCATIONS, Boolean.TRUE.toString());
  9.     properties.setProperty(ExpressionFactoryImpl.PROP_NULL_PROPERTIES, Boolean.TRUE.toString());
  10.     properties.setProperty(ExpressionFactoryImpl.PROP_IGNORE_RETURN_TYPE, Boolean.TRUE.toString());
  12.     ExpressionFactory factory = new ExpressionFactoryImpl(properties);
  14.     Map<String, Object> extMap = Maps.newHashMap();
  15.     extMap.put("foo", "bar");
  16.     ActivityEntity activityEntity = ActivityEntity.builder()
  17.         .title("我的")
  18.         .tenantId(0L)
  19.         .id(2001L)
  20.         .creator("jack")
  21.         .misName("杰克")
  22.         .modifier("sam")
  23.         .accompanys("mis/misName")
  24.         .createdTime(new Date())
  25.         .extendInfo(extMap)
  26.         .build();
  27.     ActivityDetailAr bean = ActivityDetailAr.builder()
  28.         .activityId(2001L)
  29.         .activityEntity(activityEntity)
  30.         .activityPersons(Lists.newArrayList(PersonRecordValue.builder().personName("威尔").build()))
  31.         .build();
  33.     SimpleContext context = new SimpleContext(new SimpleResolver());
  34.     // resolve bean property
  35.     context.setVariable("activityModel", factory.createValueExpression(bean, ActivityDetailAr.class));
  36.     context.setVariable("activityEntity", factory.createValueExpression(bean.getActivityEntity(), ActivityEntity.class));
  37.     System.out.println(factory.createValueExpression(context, "${activityModel.activityId}", long.class).getValue(context));
  38.     System.out.println(factory.createValueExpression(context, "${activityModel.tenantId()}", String.class).getValue(context));
  39.     System.out.println(factory.createValueExpression(context, "${activityModel.activityEntity}", ActivityEntity.class).getValue(context));
  40.     System.out.println(factory.createValueExpression(context, "${activityModel.activityEntity.id}", Long.class).getValue(context));
  41.     System.out.println(factory.createValueExpression(context, "${activityModel.activityEntity.title}", String.class).getValue(context));
  42.     System.out.println(factory.createValueExpression(context, "${activityModel.activityEntity.creator}", String.class).getValue(context));
  43.     System.out.println(factory.createValueExpression(context, "${activityModel.activityEntity.accompanys}", String.class).getValue(context));
  44.     System.out.println(factory.createValueExpression(context, "${activityEntity.title}", String.class).getValue(context));
  45.     System.out.println(factory.createValueExpression(context, "${activityEntity.misName}", String.class).getValue(context));
  46.     System.out.println(factory.createValueExpression(context, "${activityEntity.extendInfo}", Map.class).getValue(context));
  47.     System.out.println(factory.createValueExpression(context, "${activityEntity.extendInfo.foo}", String.class).getValue(context));
  48.     System.out.println(factory.createValueExpression(context, "${activityModel.activityPersons}", Object.class).getValue(context));
  49.     System.out.println(factory.createValueExpression(context, "${activityEntity.visitTime.time}", Long.class).getValue(context));
  50.     System.out.println(factory.createValueExpression(context, "${activityEntity.createdTime.time}", Long.class).getValue(context));
  51.     System.out.println(factory.createValueExpression(context, "${activityEntity.modifyTime.time}", Long.class).getValue(context));
  52. }

执行结果示例：

  1. 2001
  2. 0
  3. ActivityEntity(id=2001, tenantId=0, status=null, mis=null, misName=杰克, version=null, creator=jack, createdTime=Thu May 19 12:49:47 CST 2022, modifier=sam, modifyTime=null, daXiangCopyValue=null, visitTime=null, title=我的, visitCity=null, accompanys=mis/misName, visitInfo=null, imgUrls=null, reason=null, projectId=null, personValues=null, mainOrgValues=null, extendInfo={foo=bar})
  4. 2001
  5. 我的
  6. jack
  7. mis/misName
  8. 我的
  9. 杰克
  10. {foo=bar}
  11. bar
  12. [PersonRecordValue(tenantId=null, personId=null, personName=威尔, mainOrgId=null, mainOrgName=null, mobile=null, wechat=null, creator=null, position=null, supportOrgName=null, supportOrgName1=null, supportOrgName2=null)]
  13. 0
  14. 1652935787812
  15. 0