Jackson is "the Java JSON library" or "the best JSON parser for Java". Or simply as "JSON for Java".

Jackson Databind Source Code files are provided in the source packge (jackson-databind-2.12.4-sources.jar). You can download it at Jackson Maven Website.

You can also browse Jackson Databind Source Code below:

⏎ com/fasterxml/jackson/databind/node/FloatNode.java

package com.fasterxml.jackson.databind.node;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
import com.fasterxml.jackson.core.io.NumberOutput;
import com.fasterxml.jackson.databind.SerializerProvider;
import java.io.IOException;
import java.math.BigDecimal;
import java.math.BigInteger;

/**
 * <code>JsonNode</code> implementation for efficiently containing 32-bit
 * `float` values.
 * 
 * @since 2.2
 */
@SuppressWarnings("serial")
public class FloatNode extends NumericNode
{
    protected final float _value;

    /* 
    /**********************************************************
    /* Construction
    /**********************************************************
     */

    public FloatNode(float v) { _value = v; }

    public static FloatNode valueOf(float v) { return new FloatNode(v); }

    /* 
    /**********************************************************
    /* BaseJsonNode extended API
    /**********************************************************
     */

    @Override public JsonToken asToken() { return JsonToken.VALUE_NUMBER_FLOAT; }

    @Override
    public JsonParser.NumberType numberType() { return JsonParser.NumberType.FLOAT; }

    /* 
    /**********************************************************
    /* Overrridden JsonNode methods
    /**********************************************************
     */

    @Override
    public boolean isFloatingPointNumber() { return true; }

    @Override
    public boolean isFloat() { return true; }

    @Override public boolean canConvertToInt() {
        return (_value >= Integer.MIN_VALUE && _value <= Integer.MAX_VALUE);
    }

    @Override public boolean canConvertToLong() {
        return (_value >= Long.MIN_VALUE && _value <= Long.MAX_VALUE);
    }

    @Override // since 2.12
    public boolean canConvertToExactIntegral() {
        return !Float.isNaN(_value) && !Float.isInfinite(_value)
                && (_value == Math.round(_value));
    }

    @Override
    public Number numberValue() {
        return Float.valueOf(_value);
    }

    @Override
    public short shortValue() { return (short) _value; }

    @Override
    public int intValue() { return (int) _value; }

    @Override
    public long longValue() { return (long) _value; }

    @Override
    public float floatValue() { return _value; }

    @Override
    public double doubleValue() { return _value; }

    @Override
    public BigDecimal decimalValue() { return BigDecimal.valueOf(_value); }

    @Override
    public BigInteger bigIntegerValue() {
        return decimalValue().toBigInteger();
    }

    @Override
    public String asText() {
        return NumberOutput.toString(_value);
    }

    // @since 2.9
    @Override
    public boolean isNaN() {
        // Java 8 will have `Float.isFinite()` to combine both checks
        return Float.isNaN(_value) || Float.isInfinite(_value);
    }

    @Override
    public final void serialize(JsonGenerator g, SerializerProvider provider) throws IOException {
        g.writeNumber(_value);
    }

    @Override
    public boolean equals(Object o)
    {
        if (o == this) return true;
        if (o == null) return false;
        if (o instanceof FloatNode) {
            // We must account for NaNs: NaN does not equal NaN, therefore we have
            // to use Double.compare().
            final float otherValue = ((FloatNode) o)._value;
            return Float.compare(_value, otherValue) == 0;
        }
        return false;
    }

    @Override
    public int hashCode() {
        return Float.floatToIntBits(_value);
    }
}

⏎ com/fasterxml/jackson/databind/node/FloatNode.java

 

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