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jreuben11/pojobuilder.java

Created September 4, 2017 17:57
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Revisions

  1. jreuben11 created this gist Sep 4, 2017.
    125 changes: 125 additions & 0 deletions pojobuilder.java
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,125 @@
    private static void jCodeModelGen(Map<String, Class<?>> mapping, String className) {


    try {
    int version = 10;
    JCodeModel codeModel = new JCodeModel();
    JPackage codeModel_Package = codeModel._package("com.example.pb");
    if (className == null || className.trim().length() == 0) {
    className = "Generated" + String.valueOf(version);
    }

    JDefinedClass definedClass = codeModel_Package._class(className.trim());
    definedClass.javadoc().add("Generated class.");

    // class annotation
    definedClass.annotate(DefaultCoder.class).param("value", AvroCoder.class);

    // extend / implement MyBase
    // definedClass._implements(Serializable.class);
    definedClass._extends(MyBase.class);

    // Add constant serializable id
    definedClass.field(JMod.STATIC | JMod.FINAL, Integer.class, "modelVersion", JExpr.lit(version));

    // Add default constructor
    definedClass.constructor(JMod.PUBLIC);

    // iterate
    // JFieldVar a_Var = definedClass.field(JMod.PUBLIC, String.class, "a");
    ArrayList<JFieldVar> jFieldVars = new ArrayList<JFieldVar>();
    for (Map.Entry<String, Class<?>> entry : mapping.entrySet()) {
    String fieldName = entry.getKey();
    Class<?> fieldType = entry.getValue();
    System.out.println(fieldName + ":" + fieldType.getName());
    JFieldVar fieldVar = definedClass.field(JMod.PUBLIC, fieldType, fieldName);
    jFieldVars.add(fieldVar);
    }

    // Add parameterized constructor
    JMethod ctor_Method = definedClass.constructor(JMod.PUBLIC);
    // iterate:
    for (JFieldVar fieldVar: jFieldVars) {
    ctor_Method.param(fieldVar.type(), fieldVar.name());
    ctor_Method.body().assign(JExpr._this().ref(fieldVar.name()), JExpr.ref(fieldVar.name()));
    }


    // Add hashCode function
    JMethod hashCode_Method = definedClass.method(JMod.PUBLIC, int.class, "hashCode");
    hashCode_Method.annotate(Override.class);
    JBlock hashCode_Block = hashCode_Method.body();
    JClass HashCodeBuilder_Class = codeModel.ref(HashCodeBuilder.class);
    JVar hashCodeBuilder_Var = hashCode_Block.decl(HashCodeBuilder_Class, "hashCodeBuilder",
    JExpr._new(HashCodeBuilder_Class)
    .arg(JExpr.lit(17))
    .arg(JExpr.lit(31))
    );
    // iterate:
    for (JFieldVar fieldVar: jFieldVars) {
    hashCode_Block.add(hashCodeBuilder_Var.invoke("append").arg(fieldVar));
    }
    JInvocation toHashCode_Invocation = hashCodeBuilder_Var.invoke("toHashCode");
    hashCode_Block._return( toHashCode_Invocation);


    // Add equals function
    JMethod equals_Method = definedClass.method(JMod.PUBLIC, boolean.class, "equals");
    JVar obj = equals_Method.param(Object.class, "obj");
    equals_Method.annotate(Override.class);
    JBlock equals_Block = equals_Method.body();
    equals_Block.directStatement("if (!(obj instanceof " + className + ")) return false;");
    equals_Block.directStatement("if ((obj == this)) return true;");
    JClass EqualsBuilder_Class = codeModel.ref(EqualsBuilder.class);
    JVar rhs_Var = equals_Block.decl(definedClass, "rhs", JExpr.cast(definedClass, obj));
    JVar equalsBuilder_Var = equals_Block.decl(EqualsBuilder_Class, "equalsBuilder", JExpr._new(EqualsBuilder_Class));
    // iterate:
    for (JFieldVar fieldVar: jFieldVars) {
    equals_Block.add(equalsBuilder_Var.invoke("append").arg(fieldVar).arg(rhs_Var.ref(fieldVar)));
    }
    JInvocation isEquals_Invocation = equalsBuilder_Var.invoke("isEquals");
    equals_Block._return( isEquals_Invocation);

    JMethod toString_Method = definedClass.method(JMod.PUBLIC, String.class, "toString");
    toString_Method.annotate(Override.class);
    JBlock toString_Block = toString_Method.body();
    JClass ObjectMapper_Class = codeModel.ref(ObjectMapper.class);
    JVar objectMapper_Var = toString_Block.decl(ObjectMapper_Class, "mapper", JExpr._new(ObjectMapper_Class));
    JTryBlock tryBlock = toString_Block._try();
    tryBlock.body()._return(objectMapper_Var.invoke("writeValueAsString").arg(JExpr._this()));
    JCatchBlock catchBlock = tryBlock._catch(codeModel.ref(Exception.class));
    catchBlock.param("ex");
    catchBlock.body()._return(JExpr.lit("parsing error"));


    // Add private variable
    JFieldVar quantity = definedClass.field(JMod.PRIVATE, Integer.class, "quantity");
    // Add get method
    JMethod getter = definedClass.method(JMod.PUBLIC, quantity.type(), "getQuantity");
    getter.body()._return(quantity);
    // Add set method
    JMethod setter = definedClass.method(JMod.PUBLIC, codeModel.VOID, "setQuantity");
    setter.param(quantity.type(), quantity.name());
    setter.body().assign(JExpr._this().ref(quantity.name()), JExpr.ref(quantity.name()));

    // invoke base class method
    JMethod plusTwo = definedClass.method(JMod.PUBLIC, Integer.class, "plusTwo");
    JVar i = plusTwo.param(Integer.class, "i");
    JInvocation invoke = JExpr
    ._super()
    .invoke("plusOne")
    .arg(i);
    plusTwo.body()._return(invoke);



    // Generate the code
    codeModel.build(new File("src/main/java/"));


    } catch (JClassAlreadyExistsException ex) {
    System.out.println(ex.getMessage());
    } catch (IOException ex) {
    System.out.println(ex.getMessage());
    }
    }