Recently teaching you to deploy the ordering system Java background and ordering small program, we will always encounter a variety of problems, stone brother put you in the process of learning often encountered problems summarized here, each problem has given a solution.

Java background problems

First, the package Lombok does not exist

The solutions are as follows:

Prompt we do not install, we will install a not on the line, here to teach you how to install. 1. Click the wrench to enter the Settings page

2, SQL file cannot be executed, IDEA 2019.1 connection error (08001)

The following error is reported when connecting to the mysql database

08001 could not connection to database server

Solution:

Remove the default mysql driver and select 5.1.47 again as shown below.

The class library cannot be loaded successfully.

Some of the tripartite libraries needed for our project could not be loaded, as shown in the following figure

The solution

Let’s talk about the solution

The first kind of

  • 1. Go to the Settings page
  • 2. Use the Maven library of IDEA

    As shown above, check that IDEA comes with Maven and click OK.

  • 3, and reload the class library as shown below.

    The next step is to wait for the load, which usually takes 1-10 minutes.

The second,

If the above first method still fails to load the class library, we will use the Maven repository provided by Alibaba Cloud in China to try.

  • 1, as above, enter the Settings page first, and then as shown in the picture below. Select the aliyun configuration file we downloaded.

    The Maven configuration file of Ali Cloud has been put on the network disk for you. Some students who bought my ordering system class have entered the network disk and found this file

    Then download the file to your desktop

    Select the settins_aliyun.xml we downloaded, as shown below. Then click OK

    After this configuration, don’t forget to reload the library in our pom.xml file

    Wait patiently for the class library to load.

Fourth, the aspect library cannot be loaded down

The problem is reported as follows

< the dependency > < groupId > org. Aspectj < / groupId > < artifactId > aspectjweaver < / artifactId > < version > 1.8.13 < / version > </dependency>Copy the code

As shown in the figure below

Five, maven compile error: Java. Lang. ExceptionInInitializerError: com. Sun. View javac. Code. TypeTags

The error message is as follows:

Solution: Add the version version to the Lombok dependency library in the pom.xml file that must be greater than or equal to 1.18

Applet side related issues

First, the list of dishes cannot be displayed on ios phones.

Second, the following error is reported when placing an order

The solution is as follows

1, add the following 4 lines to the application.ym configuration file

2. Modify qcl. SQL and execute it again to generate a new database sell

create database sell default character set utf8mb4 collate utf8mb4_unicode_ci;
Copy the code

Continue to collect…