Uber H3算法封装成JAR包以及常用API调用

由于H3的库都是用C语言写的，如果想用Java代码测试，github已经有现成的H3-Java库，与H3的C库绑定好了

地址：https://github.com/uber/h3-java

比如测试代码需要调用现成H3-Java里封装好的方法，最直接的方法将h3-java打一个JAR包，具体执行 

cd h3-java
mvn package

打包的时候，会在h3-java/target目录下重新clone h3目录，比较慢，如果需要，可以提前先将h3拉下来

包打好了之后，添加到测试工程当中

此时需要调用一些H3的方法测试

比如来一个geo经纬度和h3索引之间的转换

package 大LBS系统回归测试用例库.新一代栅格系统;

import java.io.IOException;

import com.caocao.testgroup.scenariotest.BaseTest;
import com.uber.h3core.H3Core;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.Test;

/**
 * Copyright (C), scenario-test
 * FileName: H3APITest
 * Author:   lihui
 * Date:     2018/9/17
 */

public class H3APITest extends BaseTest {

    //H3所有API
    private H3Core h3;

    @BeforeClass
    public void before() throws IOException {
        h3 = H3Core.newInstance();
    }

    @Test(description = "经纬度转换为H3索引")
    public void testGeoToH3() {
        System.out.println(h3.geoToH3(30.209012, 120.208449, 8));
    }
}

这样就能正常返回对应索引

这里提供的库方法很多

可以查看com/uber/h3core/NativeMethods里定义了一堆native方法

//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//

package com.uber.h3core;

import com.uber.h3core.util.GeoCoord;
import java.util.ArrayList;
import java.util.List;

final class NativeMethods {
    NativeMethods() {
    }

    native int maxH3ToChildrenSize(long var1, int var3);

    native void h3ToChildren(long var1, int var3, long[] var4);

    native boolean h3IsValid(long var1);

    native int h3GetBaseCell(long var1);

    native boolean h3IsPentagon(long var1);

    native long geoToH3(double var1, double var3, int var5);

    native void h3ToGeo(long var1, double[] var3);

    native int h3ToGeoBoundary(long var1, double[] var3);

    native int maxKringSize(int var1);

    native void kRing(long var1, int var3, long[] var4);

    native void kRingDistances(long var1, int var3, long[] var4, int[] var5);

    native int hexRange(long var1, int var3, long[] var4);

    native int hexRing(long var1, int var3, long[] var4);

    native int h3Distance(long var1, long var3);

    native int maxPolyfillSize(double[] var1, int[] var2, double[] var3, int var4);

    native void polyfill(double[] var1, int[] var2, double[] var3, int var4, long[] var5);

    native void h3SetToLinkedGeo(long[] var1, ArrayList<List<List<GeoCoord>>> var2);

    native int compact(long[] var1, long[] var2);

    native int maxUncompactSize(long[] var1, int var2);

    native int uncompact(long[] var1, int var2, long[] var3);

    native double hexAreaKm2(int var1);

    native double hexAreaM2(int var1);

    native double edgeLengthKm(int var1);

    native double edgeLengthM(int var1);

    native long numHexagons(int var1);

    native boolean h3IndexesAreNeighbors(long var1, long var3);

    native long getH3UnidirectionalEdge(long var1, long var3);

    native boolean h3UnidirectionalEdgeIsValid(long var1);

    native long getOriginH3IndexFromUnidirectionalEdge(long var1);

    native long getDestinationH3IndexFromUnidirectionalEdge(long var1);

    native void getH3IndexesFromUnidirectionalEdge(long var1, long[] var3);

    native void getH3UnidirectionalEdgesFromHexagon(long var1, long[] var3);

    native int getH3UnidirectionalEdgeBoundary(long var1, double[] var3);
}

有兴趣的可以看下每个方法的含义，测试当中可以通过直接调用这些方法进行涉及到H3算法的测试