本代码源码为http://p2j.cn/?p=1856，园长的，然后我优化了下
首先配置idea的数据库链接，然后创建数据库的时候注意加上注释
然后新建Generate Entitys.groovy脚本

然后选择数据表，右键生成

Generate Entitys.groovy代码

import com.intellij.database.model.DasTable
import com.intellij.database.model.ObjectKind
import com.intellij.database.util.Case
import com.intellij.database.util.DasUtil

/*
 * 默认可用的 context 绑定:
 *   SELECTION   Iterable<DasObject>
 *   PROJECT     project
 *   FILES       files helper
 */

packageName = ""
typeMapping = [
        (~/(?i)tinyint|smallint|mediumint/)      : "Integer",
        (~/(?i)int/)                             : "Long",
        (~/(?i)bool|bit/)                        : "Boolean",
        (~/(?i)float|double|decimal|real/)       : "Double",
        (~/(?i)datetime|timestamp|date|time/)    : "Date",
        (~/(?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 = javaName(table.getName(), true)
    def fields = calcFields(table)
    packageName = getPackageName(dir)
    new File(dir, className + ".java").withPrintWriter { out -> generate(out, className, fields) }
}

/**
 * 获取包名称
 * @param dir 实体类所在目录
 * @return
 */
def getPackageName(dir) {
    return dir.toString().replaceAll("/", ".").replaceAll("^.*src(\\.main\\.java\\.)?", "") + ";"
}

/**
 * 实体类代码生成
 * @param out
 * @param className
 * @param fields
 * @return
 */
def generate(out, className, fields) {
    out.println "package $packageName"
    out.println ""

    Set<String> types = new HashSet<String>()

    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 "public class $className {"
    fields.each() {
        out.println ""
        if (it.annos != "") out.println "  ${it.annos}"

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

        // 输出成员变量
        out.println "\tprivate ${it.type} ${it.name};"
    }

    // 输出get/set方法
    fields.each() {
        out.println ""

        if (isNotEmpty(it.commoent)) {
            out.println "\t/**"
            out.println "\t * 获取${it.commoent}"
            out.println "\t * @return"
            out.println "\t */"
        }

        def actionName = "Boolean".equals(it.type.toString()) ? "is" : "get"

        out.println "\tpublic ${it.type} ${actionName}${it.name.capitalize()}() {"
        out.println "\t\treturn this.${it.name};"
        out.println "\t}"
        out.println ""

        if (isNotEmpty(it.commoent)) {
            out.println "\t/**"
            out.println "\t * 设置${it.commoent}"
            out.println "\t * @param ${it.name}"
            out.println "\t */"
        }
        out.println "\tpublic void set${it.name.capitalize()}(${it.type} ${it.name}) {"
        out.println "\t\tthis.${it.name} = ${it.name};"
        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
        fields += [[
                           colName : col.getName(),
                           name    : javaName(col.getName(), false),
                           type    : typeStr,
                           commoent: col.getComment(),
                           annos   : ""]]
    }
}

def javaName(str, capitalize) {
    def s = str.split(/[^\p{Alnum}]/).collect { def s = Case.LOWER.apply(it).capitalize() }.join("")
    capitalize ? s : Case.LOWER.apply(s[0]) + s[1..-1]
}

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

代码下载：Generate Entitys.groovy.zip