学习流程-2024-07

学习流程-2024-07-20

1.cordova项目添加android平台后，用android studio打开platforms/android，“在模拟器运行”按钮为灰色不可点。需要点右上角sync project with gradle files。但点了之后报错如下，下一步解决该问题：

Download https://services.gradle.org/distributions/gradle-6.8-bin.zip finished, took 8 m 20 s 611 ms (107.84 MB)
Starting Gradle Daemon...
Gradle Daemon started in 3 s 762 ms

FAILURE: Build failed with an exception.

* Where:
Script 'D:\study\cordova\project\myApp\platforms\android\CordovaLib\cordova.gradle' line: 79

* What went wrong:
A problem occurred evaluating script.
> No usable Android build tools found. Highest 34.x installed version is 33.0.2; Recommended version is 34.0.0.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 13s

学习流程2024-07-21

1.卸载Android studio 3.5.2，安装Android studio 2024.1.1。用2024.1.1打开项目仍有报错，正在排查，后面确定一下2024.1.1的sdk要配成和电脑中已有的2021.1.1一样的sdk吗？

学习流程2024-07-23

1.练习前后端传参

后端BookApiController.java：

/**
 * 一开始我的是错误的：@RestController("/api/bookApiController")
 *
 * 分析："/api/bookApiController"这种一定是@RequestMapping注解后面的
 */
@RestController
@RequestMapping("/api/bookApiController")
public class BookApiController {

    /**
     * 练习前后端传参，无具体service层代码
     * 
     * 我一开始的错误写法：@RequestMapping(value = "deleteBookById", method = RequestMethod.DELETE)
     * 会报404
     * 
     * 且一开始没加@ResponseBody，报404，初步分析是在目前这框架中，@RestController不能达到替换@Controller+@ResponseBody的效果？
     * @param id
     * @return
     */
    @RequestMapping(value = "deleteBookById/{id}", method = RequestMethod.DELETE)
    @ResponseBody
    public PracticeAjaxJson deleteBookById(@PathVariable("id") String id) {
        PracticeAjaxJson j = new PracticeAjaxJson();
        j.setMsg("删除成功");
        try {
            System.out.println("id from frontEnd: " + id);
            j.setSuccess(true);
        } catch (Exception e) {
            j.setSuccess(false);
            j.setMsg(e.getMessage());
        }
        return j;
    }

    /**
     * 练习前后端传参，无具体service层代码
     * @param id
     * @return
     */
    @RequestMapping(value = "deleteBookByIdWithError/{id}", method = RequestMethod.DELETE)
    @ResponseBody
    public PracticeAjaxJson deleteBookByIdWithError(@PathVariable("id") String id) {
        PracticeAjaxJson j = new PracticeAjaxJson();
        j.setMsg("删除成功");
        try {
            System.out.println("id from frontEnd: " + id);
            int number = 0;
            int result = 2 / number;
            j.setSuccess(true);
        } catch (Exception e) {
            j.setSuccess(false);
            j.setMsg(e.getMessage());
        }
        return j;
    }

}

用于响应前端的PracticeAjaxJson.java：

public class PracticeAjaxJson {
    private boolean success;
    private String msg = "操作成功";

    public boolean isSuccess() {
        return success;
    }

    public void setSuccess(boolean success) {
        this.success = success;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }
}

前端：

<template>
  <f7-page>
    <button @click="practiceDeleteBook()">验证前后端传参（正常请求）</button>
    <button @click="practiceDeleteBookWithError()">验证前后端传参（模拟后端报错）</button>
  </f7-page>
</template>

<script>
export default {
  methods: {
    practiceDeleteBook() {
      const _self = this;
      const id = 'bookId0723';
      _self.request.delete({
        url: '/bookApiController/deleteBookById/' + id
      }).then(function(response) {
        if (response.data.success) {
          messagef7(response.data.msg);
        }
      }).catch((error) => {
        console.log(error);
      })
    },
    /**
     * 没按我期望的进入.catch((error) => {})里，下一步确认。
     */
    practiceDeleteBookWithError() {
      const _self = this;
      const id = 'bookId0723';
      _self.request.delete({
        url: '/bookApiController/deleteBookByIdWithError/' + id
      }).then((response) => {
        debugger
        if (response.data.success) {
          messagef7(response.data.msg);
        }
      }).catch((error) => {
        debugger
        console.log(error);
      })
    }
}
</script>