一、安装postgres
sudo yum install -y https://download.postgresql.org/pub/repos/yum/reporpms/EL-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm
sudo yum install -y postgresql11-server
sudo /usr/pgsql-11/bin/postgresql-11-setup initdb
sudo systemctl enable postgresql-11
sudo systemctl start postgresql-11
yum install -y postgresql11-libs postgresql11 postgresql11-devel
yum -y install postgresql11-contrib postgresql11-server

yum install gcc gcc-c++
二、安装openjdk
三、安装mvn

三、下载pljava，链接为git clone https://github.com/tada/pljava
cd pljava
mvn clean install（mvn -Dpgsql.pgconfig=/usr/pgsql-11/bin/pg_config clean install）

四、设置pljava.libjvm_location
cd /var/lib/pgsql/11/data/
pljava.libjvm_location=‘/usr/soft/openjdk11/lib/server/libjvm.so’

修改pg_hba.conf

自定义函数开发

package test;

public class function {
    public static String hello(String str){
        return "hello : " + str;
    }

    public static int arraycount(String[] arr){
        return arr.length;
    }

    public static void main(String[] args) {
        System.out.println(hello("123456"));
    }
}

引用文件
select sqlj.install_jar(‘file:///pljava/pgjava.jar’,‘hello’,true);
更新jar包
— select sqlj.replace_jar(‘file:///pljava/pgjava.jar’,‘hello’,true);
Set schema下的类
select sqlj.set_classpath(‘public’,‘hello’);
创建function
create function sayhello(varchar) returns varchar as ‘test.function.hello’ language java;
drop function sayhello(varchar);