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Spring_@Scope("prototype&qu

Spring_@Scope("prototype&qu

作者: 大鹏_xzlp | 来源:发表于2017-09-28 16:32 被阅读1761次
    1. 我们先看一种最普通的情况 model和Controller都是单例
    @Component
    public class Order {
        private String orderNum = "12";
    
        public String getOrderNum() {
            return orderNum;
        }
    
        public void setOrderNum(String orderNum) {
            this.orderNum = orderNum;
        }
    
        @Override
        public String toString() {
            return "Order{" +
                    "orderNum='" + orderNum + '\'' +
                    '}';
        }
    }
    
    @Controller
    @RequestMapping(value = "/api")
    public class MainController {
        @Autowired
        private Order order;
        private String name;
    
        @RequestMapping(value = "/users/{username}",method = RequestMethod.GET)
        @ResponseBody
        public String userProfile(@PathVariable("username") String username) {
            name = username;
            order.setOrderNum( name);
    
            try {
                for(int i = 0; i < 100; i++) {
                    System.out.println(Thread.currentThread().getId() + "name:" + name + "--order:" + order.getOrderNum());
                    Thread.sleep(2000);
                }
            } catch (Exception e) {
            }
            return order.toString();
        }
    }
    

    我们分别发送两个请求

    http://localhost:8080/api/users/aaa
    http://localhost:8080/api/users/bbb

    29name:aaa--order:aaa
    29name:aaa--order:aaa
    29name:aaa--order:aaa
    31name:bbb--order:bbb
    29name:bbb--order:bbb
    31name:bbb--order:bbb
    

    可以看到当第二个请求发送后,29线程里的name和order都发生了改变,因为当前的Order和Controller都是单例

    1. 情况二 model是单例 Controller不是单例
    @Component
    public class Order {
        private String orderNum = "12";
    
        public String getOrderNum() {
            return orderNum;
        }
    
        public void setOrderNum(String orderNum) {
            this.orderNum = orderNum;
        }
    
        @Override
        public String toString() {
            return "Order{" +
                    "orderNum='" + orderNum + '\'' +
                    '}';
        }
    }
    
    @Controller
    @RequestMapping(value = "/api")
    @Scope("prototype")
    public class MainController {
        @Autowired
        private Order order;
        private String name;
    
        @RequestMapping(value = "/users/{username}",method = RequestMethod.GET)
        @ResponseBody
        public String userProfile(@PathVariable("username") String username) {
            name = username;
            order.setOrderNum( name);
    
            try {
                for(int i = 0; i < 100; i++) {
                    System.out.println(Thread.currentThread().getId() + "name:" + name + "--order:" + order.getOrderNum());
                    Thread.sleep(2000);
                }
            } catch (Exception e) {
            }
            return order.toString();
        }
    }
    
    28name:aaa--order:aaa
    28name:aaa--order:aaa
    29name:bbb--order:bbb
    28name:aaa--order:bbb
    29name:bbb--order:bbb
    28name:aaa--order:bbb
    

    可以看到第二个请求发送后,28线程中的name还是aaa没有发生变化,而order受到了影响,发生了变化,因为Controller是一个新的,所以name也是一个新的变量,但是order是单例的

    3.情况三 model不是单例 Controller是单例

    @Component
    @Scope("prototype")
    public class Order {
        private String orderNum = "12";
    
        public String getOrderNum() {
            return orderNum;
        }
    
        public void setOrderNum(String orderNum) {
            this.orderNum = orderNum;
        }
    
        @Override
        public String toString() {
            return "Order{" +
                    "orderNum='" + orderNum + '\'' +
                    '}';
        }
    }
    
    @Controller
    @RequestMapping(value = "/api")
    public class MainController {
        @Autowired
        private Order order;
        private String name;
    
        @RequestMapping(value = "/users/{username}",method = RequestMethod.GET)
        @ResponseBody
        public String userProfile(@PathVariable("username") String username) {
            name = username;
            order.setOrderNum( name);
    
            try {
                for(int i = 0; i < 100; i++) {
                    System.out.println(Thread.currentThread().getId() + "name:" + name + "--order:" + order.getOrderNum());
                    Thread.sleep(2000);
                }
            } catch (Exception e) {
            }
            return order.toString();
        }
    }
    
    29name:aaa--order:aaa
    29name:aaa--order:aaa
    30name:bbb--order:bbb
    29name:bbb--order:bbb
    30name:bbb--order:bbb
    

    可以看到name和order都变了,可见只设置Model是没有用的

    4.情况四 Controller和Model都设置不是单例

    @Component
    @Scope("prototype")
    public class Order {
        private String orderNum = "12";
    
        public String getOrderNum() {
            return orderNum;
        }
    
        public void setOrderNum(String orderNum) {
            this.orderNum = orderNum;
        }
    
        @Override
        public String toString() {
            return "Order{" +
                    "orderNum='" + orderNum + '\'' +
                    '}';
        }
    }
    
    @Controller
    @RequestMapping(value = "/api")
    @Scope("prototype")
    public class MainController {
        @Autowired
        private Order order;
        private String name;
    
        @RequestMapping(value = "/users/{username}",method = RequestMethod.GET)
        @ResponseBody
        public String userProfile(@PathVariable("username") String username) {
            name = username;
            order.setOrderNum( name);
    
            try {
                for(int i = 0; i < 100; i++) {
                    System.out.println(Thread.currentThread().getId() + "name:" + name + "--order:" + order.getOrderNum());
                    Thread.sleep(2000);
                }
            } catch (Exception e) {
            }
            return order.toString();
        }
    }
    
    28name:aaa--order:aaa
    28name:aaa--order:aaa
    29name:bbb--order:bbb
    28name:aaa--order:aaa
    29name:bbb--order:bbb
    28name:aaa--order:aaa
    

    这样29请求的和28请求的就完全分开了

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