idea 使用 -- 使用ideaMysql连接数据库，并生成实体类

创建数据库连接，如果侧栏没有database，可以在plugins中看插件是否开启

拓展一下，使用MybatisX插件生产（零代码，比下边这个更灵活）

链接 --》Mybatis-X插件自动生成代码的使用详解（小白专用）

上边都操作完之后是这样

你如果是第一次， 会直接提示你下载，不是我这个switch to  latest driver，下载就好了

我这个怎么解决 ↓ ↓ 选择最新的就行

然后 apply  返回上去，再测试连接

连接成功之后，

 生成默认实体类，注意生成位置是你源码对应实体类包

看这优秀的包名优秀的类名优秀的数据类型，没得序列化接口，没得equals，没得tostring

救星来了

这个文件，在同目录下复制一,代码如下（对不起小白尽力了，包名多个点麻烦大佬们自己删一下）。

import com.intellij.database.model.DasTable
import com.intellij.database.model.ObjectKind
import com.intellij.database.util.Case
import com.intellij.database.util.DasUtil
import java.io.*
import java.text.SimpleDateFormat

/*
 * Available context bindings:
 *   SELECTION   Iterable
 *   PROJECT     project
 *   FILES       files helper
 */
packageName = ""
typeMapping = [
        (~/(?i)tinyint|smallint|mediumint/)      : "Integer",
        (~/(?i)int/)                             : "Integer",
        (~/(?i)bool|bit/)                        : "Boolean",
        (~/(?i)float|double|decimal|real/)       : "Double",
        (~/(?i)datetime|timestamp|date|time/)    : "String",
        (~/(?i)blob|binary|bfile|clob|raw|image/): "InputStream",
        (~/(?i)/)                                : "String"
]


FILES.chooseDirectoryAndSave("Choose directory", "Choose where to store generated files") { dir ->
    SELECTION.filter { it instanceof DasTable && it.getKind() == ObjectKind.TABLE }.each { generate(it, dir) }
}

def generate(table, dir) {
    def className = javaClassName(table.getName(), true)
    // def className = javaName(table.getName(), true)
    def fields = calcFields(table)
    packageName = getPackageName(dir)
    PrintWriter printWriter = new PrintWriter(new OutputStreamWriter(new FileOutputStream(new File(dir, className + ".java")), "UTF-8"))
    printWriter.withPrintWriter { out -> generate(out, className, fields, table) }

//    new File(dir, className + ".java").withPrintWriter { out -> generate(out, className, fields,table) }
}

// 获取包所在文件夹路径
def getPackageName(dir) {
    return dir.toString().replaceAll("\\\\", ".").replaceAll("/", ".").replaceAll("^.*src(\\.main\\.java\\.)?", "") + ";"
}

def generate(out, className, fields, table) {
    def tableName = table.getName()
    out.println "package $packageName"
    out.println ""
    out.println "import java.io.Serializable;"
    out.println "import com.baomidou.mybatisplus.annotation.TableName;"
    out.println "import com.fasterxml.jackson.annotation.JsonIgnoreProperties;"
    out.println "import com.fasterxml.jackson.annotation.JsonInclude;"
    out.println "import lombok.NoArgsConstructor;"
    out.println "import lombok.EqualsAndHashCode;"
    out.println "import lombok.Getter;"
    out.println "import lombok.Setter;"
    out.println "import lombok.ToString;"

    Set types = new HashSet()

    fields.each() {
        types.add(it.type)
    }

    if (types.contains("Date")) {
        out.println "import java.util.Date;"
    }

    if (types.contains("InputStream")) {
        out.println "import java.io.InputStream;"
    }
    out.println ""
    out.println "/**\n" +
            " * @Description  \n" +
            " * @Author  \n" +
            " * @Date " + new SimpleDateFormat("yyyy-MM-dd").format(new Date()) + " \n" +
            " */"
    out.println "@Getter"
    out.println "@Setter"
    out.println "@ToString"
    out.println "@NoArgsConstructor"
    out.println "@EqualsAndHashCode"
    out.println "@JsonInclude(JsonInclude.Include.NON_NULL)"
    out.println "@JsonIgnoreProperties(value = {\"hibernateLazyInitializer\", \"handler\", \"fieldHandler\"}, ignoreUnknown = true)"
    out.println "@TableName(\"" + table.getName() + "\")"
    out.println "public class $className implements Serializable {"
    out.println genSerialID()


    fields.each() {
        out.println ""
        // 输出注释
        if (isNotEmpty(it.commoent)) {
            out.println "\t/**"
            out.println "\t * ${it.commoent.toString()}"
            out.println "\t */"
        }

        if (it.annos != "") out.println "   ${it.annos.replace("[@Id]", "")}"

        if (("id").equalsIgnoreCase(it.name) || (it.name.contains("Id") && !it.type.equals("String"))) {
            // 输出成员变量
            // out.println "\tprivate Long ${it.name};"
            out.println "\tprivate ${it.type} ${it.name};"
        } else {
            out.println "\tprivate ${it.type} ${it.name};"
        }

    }

    // 输出get/set方法
//    fields.each() {
//        out.println ""
//        out.println "\tpublic ${it.type} get${it.name.capitalize()}() {"
//        out.println "\t\treturn this.${it.name};"
//        out.println "\t}"
//        out.println ""
//
//        out.println "\tpublic void set${it.name.capitalize()}(${it.type} ${it.name}) {"
//        out.println "\t\tthis.${it.name} = ${it.name};"
//        out.println "\t}"
//    }
    // toString方法
//    out.println "\t@Override"
//    out.println "\tpublic String toString() {"
//    out.print "\t\t return "
//    out.print "\"$className"
//    out.println "{\"+ "
//    fields.each() {
//        out.println "\t\t\t\", ${it.name}='\" + ${it.name} + '\\'' +"
//    }
//    out.println "\t\t'}\';"
//    out.println "\t}"

    out.println "}"
    out.println ""
}

def calcFields(table) {
    DasUtil.getColumns(table).reduce([]) { fields, col ->
        def spec = Case.LOWER.apply(col.getDataType().getSpecification())

        def typeStr = typeMapping.find { p, t -> p.matcher(spec).find() }.value
        def comm = [
                colName : col.getName(),
                name    : javaName(col.getName(), false),
                type    : typeStr,
                commoent: col.getComment(),
                annos   : ""]
        fields += [comm]
    }
}

// 处理类名（这里是因为我的表都是以t_命名的，所以需要处理去掉生成类名时的开头的tb，
// 如果你不需要那么请查找用到了 javaClassName这个方法的地方修改为 javaName 即可）
def javaClassName(str, capitalize) {
    def s = com.intellij.psi.codeStyle.NameUtil.splitNameIntoWords(str)
            .collect { Case.LOWER.apply(it).capitalize() }
            .join("")
            .replaceAll(/[^\p{javaJavaIdentifierPart}[_]]/, "_")
    // 去除开头的tb
  //如果 t_开头，下边的2改为1
    s = s[2..s.size() - 1]
    capitalize || s.length() == 1 ? s : Case.LOWER.apply(s[0]) + s[1..-1]
}

def javaName(str, capitalize) {
//    def s = str.split(/(?<=[^\p{IsLetter}])/).collect { Case.LOWER.apply(it).capitalize() }
//            .join("").replaceAll(/[^\p{javaJavaIdentifierPart}]/, "_")
//    capitalize || s.length() == 1? s : Case.LOWER.apply(s[0]) + s[1..-1]
    def s = com.intellij.psi.codeStyle.NameUtil.splitNameIntoWords(str)
            .collect { Case.LOWER.apply(it).capitalize() }
            .join("")
            .replaceAll(/[^\p{javaJavaIdentifierPart}[_]]/, "_")
    capitalize || s.length() == 1 ? s : Case.LOWER.apply(s[0]) + s[1..-1]
}

def isNotEmpty(content) {
    return content != null && content.toString().trim().length() > 0
}

static String changeStyle(String str, boolean toCamel) {
    if (!str || str.size() <= 1)
        return str

    if (toCamel) {
        String r = str.toLowerCase().split('_').collect { cc -> Case.LOWER.apply(cc).capitalize() }.join('')
        return r[0].toLowerCase() + r[1..-1]
    } else {
        str = str[0].toLowerCase() + str[1..-1]
        return str.collect { cc -> ((char) cc).isUpperCase() ? '_' + cc.toLowerCase() : cc }.join('')
    }
}

static String genSerialID() {
    return "\tprivate static final long serialVersionUID =  " + Math.abs(new Random().nextLong()) + "L;"
}

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补充一下发现的异常

 解决办法就是在url后边加上?useSSL=false 就可以了

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