monzou / grinder

Grind Java beans by annotation processor

Grinder - Grind Java Beans by APT

Grinder provides bean property accessors by APT

Motivation

Sometimes Java programmers have to write com.google.common.base.Function to access bean property. This is necessary but it's boring. So we made Grinder to generate bean meta classes automatically. Grinder provides following functions:

• BeanPropertyAccessor to read-only property
• BeanProperty to writable property

How to use

Add @Grind annotation to your bean class.

Bean

@Grind
public class Trade implements Serializable {

    private final Long id;

    private String tradeNo;

    private long version;

    private boolean deleted;

    public Trade(Long id) {
        this.id = id;
    }

    public String getTradeNo() {
        return tradeNo;
    }

    public void setTradeNo(String tradeNo) {
        this.tradeNo = tradeNo;
    }

    public long getVersion() {
        return version;
    }

    public void setVersion(long version) {
        this.version = version;
    }

    public boolean isDeleted() {
        return deleted;
    }

    public void setDeleted(boolean deleted) {
        this.deleted = deleted;
    }

    public Long getId() {
        return id;
    }

}

Generated meta class

public class TradeMeta {

    /** tradeNo */
    public static final BeanProperty<Trade, java.lang.String> tradeNo = new BeanProperty<Trade, java.lang.String>() {

        /** {@inheritDoc} */
        @Override
        public java.lang.String getName() {
            return "tradeNo";
        }

        /** {@inheritDoc} */
        @Override
        public java.lang.String apply(Trade bean) {
            return bean.getTradeNo();
        }

        /** {@inheritDoc} */
        @Override
        public Trade apply(Trade bean, java.lang.String tradeNo) {
            bean.setTradeNo(tradeNo);
            return bean;
        }

    };

    /** version */
    public static final BeanProperty<Trade, java.lang.Long> version = new BeanProperty<Trade, java.lang.Long>() {

        /** {@inheritDoc} */
        @Override
        public java.lang.String getName() {
            return "version";
        }

        /** {@inheritDoc} */
        @Override
        public java.lang.Long apply(Trade bean) {
            return bean.getVersion();
        }

        /** {@inheritDoc} */
        @Override
        public Trade apply(Trade bean, java.lang.Long version) {
            bean.setVersion(version);
            return bean;
        }

    };

    /** deleted */
    public static final BeanProperty<Trade, java.lang.Boolean> deleted = new BeanProperty<Trade, java.lang.Boolean>() {

        /** {@inheritDoc} */
        @Override
        public java.lang.String getName() {
            return "deleted";
        }

        /** {@inheritDoc} */
        @Override
        public java.lang.Boolean apply(Trade bean) {
            return bean.isDeleted();
        }

        /** {@inheritDoc} */
        @Override
        public Trade apply(Trade bean, java.lang.Boolean deleted) {
            bean.setDeleted(deleted);
            return bean;
        }

    };


    /** id */
    public static final BeanPropertyAccessor<Trade, java.lang.Long> id = new BeanPropertyAccessor<Trade, java.lang.Long>() {

        /** {@inheritDoc} */
        @Override
        public java.lang.String getName() {
            return "id";
        }

        /** {@inheritDoc} */
        @Override
        public java.lang.Long apply(Trade bean) {
            return bean.getId();
        }

    };

    private static final Map<String, BeanProperty<? super Trade, ?>> properties;

    private static final Map<String, BeanPropertyAccessor<? super Trade, ?>> propertyAccessors;

    static {

        Builder<String, BeanProperty<? super Trade, ?>> propertiesBuilder = ImmutableMap.builder();
        propertiesBuilder.put("tradeNo", tradeNo);
        propertiesBuilder.put("version", version);
        propertiesBuilder.put("deleted", deleted);
        properties = propertiesBuilder.build();

        Builder<String, BeanPropertyAccessor<? super Trade, ?>> propertyAccessorsBuilder = ImmutableMap.builder();
        propertyAccessorsBuilder.put("id", id);
        propertyAccessors = propertyAccessorsBuilder.build();

    }

    /**
     * Get all properties
     *
     * @return properties
     */
    public static List<BeanProperty<? super Trade, ?>> getProperties() {
        return ImmutableList.copyOf(properties.values());
    }

    /**
     * Get all property accessors
     *
     * @return property accessors
     */
    public static List<BeanPropertyAccessor<? super Trade, ?>> getPropertyAccessors() {
        ImmutableList.Builder<BeanPropertyAccessor<? super Trade, ?>> builder = ImmutableList.builder();
        builder.addAll(properties.values());
        builder.addAll(propertyAccessors.values());
        return builder.build();
    }

    /**
     * Get the bean property by name
     *
     * @param propertyName property name
     * @return {@link BeanProperty}
     */
    public static BeanProperty<? super Trade, ?> getProperty(String propertyName) {
        return properties.get(propertyName);
    }

    /**
     * Get the bean property accessor by name
     *
     * @param propertyName property name
     * @return {@link BeanPropertyAccessor}
     */
    public static BeanPropertyAccessor<? super Trade, ?> getPropertyAccessor(String propertyName) {
        BeanPropertyAccessor<? super Trade,?> property = getProperty(propertyName);
        if (property == null) {
            property = propertyAccessors.get(propertyName);
        }
        return property;
    }

}

BeanProperty and BeanPropertyAccessor extends com.google.common.base.Function. So you can use it like this:

List<Trade> trades = Trade.findAll();
List<String> tradeNos = FluentIterable.from(trades).filter(Predicates.not(Predicates2.fromFunction(TradeMeta.deleted))).transform(TradeMeta.tradeNo).toList();

Installation

1. Add Maven repository: http://monzou.github.com/maven-repository/
2. Add dependency: com.github.monzou:grinder:${version}

Configuration example for Gradle:

repositories {
    maven {
        url "http://monzou.github.com/maven-repository/"
    }
}
dependencies {
    compile "com.github.monzou:grinder:${version}"
}

Requirements

• JDK 7 +

Dependencies

• Google Guava

License

(The MIT License)

Copyright (c) 2014 Takuro Monji @monzou