{"id":1528,"date":"2016-09-01T14:17:15","date_gmt":"2016-09-01T14:17:15","guid":{"rendered":"http:\/\/codethataint.com\/blog\/?p=1528"},"modified":"2016-09-01T17:18:49","modified_gmt":"2016-09-01T17:18:49","slug":"spring-annotations1","status":"publish","type":"post","link":"https:\/\/codethataint.com\/blog\/spring-annotations1\/","title":{"rendered":"Spring Annotations1"},"content":{"rendered":"

@Required<\/strong>
\nIncase the bean value is not defined using required will display the spring error message instead of null pointer exception for the bean whose value is not defined.<\/p>\n

spring.xml<\/strong><\/p>\n

\r\n<bean class="com.mugil.shapes.Circle" id="circleId">\t\t\r\n<\/bean>\r\n<\/pre>\n
Note above the pointA is undefined for above circle bean<\/em><\/p>\n
Spring Error without @Required annotation<\/strong><\/p>\n
\r\nException in thread \"main\" java.lang.NullPointerException\r\n\tat com.mugil.shapes.Circle.drawShape(Circle.java:11)\r\n\tat com.mugil.shapes.DrawingApp.main(DrawingApp.java:17)\r\n<\/pre>\n
circle.java<\/strong><\/p>\n
\r\npublic class Circle implements Shape{\r\n\tprivate Point center;\r\n\t\r\n\t@Override\r\n\tpublic void drawShape() {\r\n\t\tSystem.out.println("Shape of Circle ");\r\n\t\tSystem.out.println("Center of Cirlce "+ getCenter().getX() + " - " + getCenter().getY());\r\n\t}\r\n\r\n\tpublic Point getCenter() {\r\n\t\treturn center;\r\n\t}\r\n\r\n\t@Required\r\n\tpublic void setCenter(Point center) {\r\n\t\tthis.center = center;\r\n\t}\t\t\r\n}\r\n\r\n<\/pre>\n
spring.xml<\/strong><\/p>\n
\r\n<bean class="com.mugil.shapes.Circle" id="circleId">\t\t\r\n<\/bean>\r\n\t\r\n<bean class="org.springframework.beans.factory.annotation.RequiredAnnotationBeanPostProcessor"\/>\r\n<\/pre>\n
Spring Error is Thrown<\/strong><\/p>\n
\r\nException in thread \"main\" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'circleId' defined in class path resource [spring1.xml]: Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanInitializationException: Property 'center' is required for bean 'circleId'\r\n<\/pre>\n
Autowired Annotation<\/strong><\/p>\n
    \n
  1. @Autowired works by taking into consideration type,name,qualifier<\/li>\n
  2. If type not found name will be considered<\/li>\n<\/ol>\n
    spring.xml(by Type)<\/strong><\/p>\n
    \r\n<beans>\r\n\t<bean id="PointA" class="com.mugil.shapes.Point">\r\n\t\t<property name="x" value="0"\/>\r\n\t\t<property name="y" value="20"\/>\r\n\t<\/bean>\t\r\n\t<bean class="com.mugil.shapes.Circle" id="circleId"><\/bean>\t\r\n\t<bean class="org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor"\/>\r\n<\/beans>\r\n<\/pre>\n
    spring.xml(by Name)<\/strong><\/p>\n
    \r\n<beans>\r\n\t<bean id="center" class="com.mugil.shapes.Point">\r\n\t\t<property name="x" value="0"\/>\r\n\t\t<property name="y" value="20"\/>\r\n\t<\/bean>\t\r\n\t<bean class="com.mugil.shapes.Circle" id="circleId"><\/bean>\t\r\n\t<bean class="org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor"\/>\r\n<\/beans>\r\n<\/pre>\n
    In above xml center is the name of instance variable in circle class
    \nspring.xml(by Qualifier)<\/strong><\/p>\n
    \r\n<?xml version="1.0" encoding="UTF-8"?>\r\n<beans xmlns="http:\/\/www.springframework.org\/schema\/beans"\r\n\txmlns:xsi="http:\/\/www.w3.org\/2001\/XMLSchema-instance" xmlns:context="http:\/\/www.springframework.org\/schema\/context"\r\n\txsi:schemaLocation="http:\/\/www.springframework.org\/schema\/beans \r\n\t    http:\/\/www.springframework.org\/schema\/beans\/spring-beans-2.5.xsd\r\n\t\thttp:\/\/www.springframework.org\/schema\/context \r\n\t\thttp:\/\/www.springframework.org\/schema\/context\/spring-context-2.5.xsd">\t\t\r\n\t<bean id="pointA" class="com.mugil.shapes.Point">\r\n\t\t<qualifier value="circle"\/>\t\t\t\r\n\t\t<property name="x" value="20"\/>\r\n\t\t<property name="y" value="0"\/>\r\n\t<\/bean>\t\r\n\t<bean class="com.mugil.shapes.Circle" id="circleId"><\/bean>\t\r\n\t<bean class="org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor"\/>\r\n<\/beans>\r\n<\/pre>\n
    circle.java<\/strong><\/p>\n
    \r\npublic class Circle implements Shape{\r\n\t@Autowired\r\n\t@Qualifier("circle")\r\n\tprivate Point center;\r\n\t\r\n\t@Override\r\n\tpublic void drawShape() {\r\n\t\tSystem.out.println("Shape of Circle ");\r\n\t\tSystem.out.println("Center of Cirlce "+ getCenter().getX() + " - " + getCenter().getY());\r\n\t}\r\n\r\n\tpublic Point getCenter() {\r\n\t\treturn center;\r\n\t}\r\n\t\r\n\tpublic void setCenter(Point center) {\r\n\t\tthis.center = center;\r\n\t}\t\t\r\n}\r\n\r\n<\/pre>\n","protected":false},"excerpt":{"rendered":"
    @Required Incase the bean value is not defined using required will display the spring error message instead of null pointer exception for the bean whose value is not defined. spring.xml <bean class="com.mugil.shapes.Circle" id="circleId"> <\/bean> Note above the pointA is undefined for above circle bean Spring Error without @Required annotation Exception in thread “main” java.lang.NullPointerException at… Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[189],"tags":[],"class_list":["post-1528","post","type-post","status-publish","format-standard","hentry","category-form-elements-spring"],"_links":{"self":[{"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/posts\/1528","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/comments?post=1528"}],"version-history":[{"count":3,"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/posts\/1528\/revisions"}],"predecessor-version":[{"id":1531,"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/posts\/1528\/revisions\/1531"}],"wp:attachment":[{"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/media?parent=1528"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/categories?post=1528"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/codethataint.com\/blog\/wp-json\/wp\/v2\/tags?post=1528"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}