PostgreSQL, Second Edition

PL/Java—Writing Stored Procedures in Java

PL/Java is a procedural language. When you write a PL/Java function, you write normal Java code, compile it to bytecode form (that is, compile the source code into a .class file), store the compiled form in a Java archive file (a .jar file), and then load that archive into the database. When you execute a PL/Java function, the PL/Java call handler creates a Java Virtual Machine (JVM) within the PostgreSQL server process and then asks the JVM execute the bytecode form of your function. A PL/Java function corresponds to a method of some Java class. Since a PL/Java function is a Java method, you can use Java control structures, Java classes, Java data types, Java functions, and Java interfaces. In fact, ...