Spring_@Scope("prototype")

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

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

Spring_@Scope("prototype")

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