本文介绍如何使用Java实现SHP文件与GeoJSON文件之间的相互转换，并提供了一个示例，展示如何将Excel文件转换为SHP文件。
当我们在使用的的的的OpenLayers的时候，我们需要有需要以以以GeoJSON的的数据。但是我们手里只有.SHP的文件。此时我们很苦恼，现在我来拯救你来了。
**
* shp转换为Geojson
* @param shpPath
* @return
*/
public Map shape2Geojson(String shpPath, String jsonPath){
Map map = new HashMap();
FeatureJSON fjson = new FeatureJSON();
try{
StringBuffer sb = new StringBuffer();
sb.append("{\"type\": \"FeatureCollection\",\"features\": ");
File file = new File(shpPath);
ShapefileDataStore shpDataStore = null;
shpDataStore = new ShapefileDataStore(file.toURL());
//设置编码
Charset charset = Charset.forName("GBK");
shpDataStore.setStringCharset(charset);
String typeName = shpDataStore.getTypeNames()[0];
SimpleFeatureSource featureSource = null;
featureSource = shpDataStore.getFeatureSource (typeName);
SimpleFeatureCollection result = featureSource.getFeatures();
SimpleFeatureIterator itertor = result.features();
JSONArray array = new JSONArray();
while (itertor.hasNext())
{
SimpleFeature feature = itertor.next();
StringWriter writer = new StringWriter();
fjson.writeFeature(feature, writer);
JSONObject json = new JSONObject(writer.toString());
array.put(json);
}
itertor.close();
sb.append(array.toString());
sb.append("}");
//写入文件
cm.append2File(jsonPath, sb.toString());
map.put("status", "success");
map.put("message", sb.toString());
}
catch(Exception e){
map.put("status", "failure");
map.put("message", e.getMessage());
e.printStackTrace();
}
return map;
} 有时，我们在需要的.SHP文件的时候，此时手里面又只有以GeoJSON的的的的文件。此时我这里又派上作用了。
/**
* geojson转换为shp文件
* @param jsonPath
* @param shpPath
* @return
*/
public Map geojson2Shape(String jsonPath, String shpPath){
Map map = new HashMap();
GeometryJSON gjson = new GeometryJSON();
try{
String strJson = cm.getFileContent(jsonPath);
JSONObject json = new JSONObject(strJson);
JSONArray features = (JSONArray) json.get("features");
JSONObject feature0 = new JSONObject(features.get(0).toString());
System.out.println(feature0.toString());
String strType = ((JSONObject)feature0.get("geometry")).getString("type").toString();
Class<?> geoType = null;
switch(strType){
case "Point":
geoType = Point.class;
case "MultiPoint":
geoType = MultiPoint.class;
case "LineString":
geoType = LineString.class;
case "MultiLineString":
geoType = MultiLineString.class;
case "Polygon":
geoType = Polygon.class;
case "MultiPolygon":
geoType = MultiPolygon.class;
}
//创建shape文件对象
File file = new File(shpPath);
Map<String, Serializable> params = new HashMap<String, Serializable>();
params.put( ShapefileDataStoreFactory.URLP.key, file.toURI().toURL() );
ShapefileDataStore ds = (ShapefileDataStore) new ShapefileDataStoreFactory().createNewDataStore(params);
//定义图形信息和属性信息
SimpleFeatureTypeBuilder tb = new SimpleFeatureTypeBuilder();
tb.setCRS(DefaultGeographicCRS.WGS84);
tb.setName("shapefile");
tb.add("the_geom", geoType);
tb.add("POIID", Long.class);
ds.createSchema(tb.buildFeatureType());
//设置编码
Charset charset = Charset.forName("GBK");
ds.setStringCharset(charset);
//设置Writer
FeatureWriter<SimpleFeatureType, SimpleFeature> writer = ds.getFeatureWriter(ds.getTypeNames()[0], Transaction.AUTO_COMMIT);
for(int i=0,len=features.length();i<len;i++){
String strFeature = features.get(i).toString();
Reader reader = new StringReader(strFeature);
SimpleFeature feature = writer.next();
//这里看geojson是什么类型的。这里的readMultiLine才知道是什么的样的。否则会出现错误。
feature.setAttribute("the_geom",gjson.readMultiLine(reader));
// Object readMulti = null;
// switch(strType){
// case "Point":
// readMulti=gjson.readPoint(reader);
// case "MultiPoint":
// readMulti=gjson.readMultiPoint(reader);
// case "LineString":
// readMulti=gjson.readLine(reader);
// case "MultiLineString":
// readMulti=gjson.readMultiLine(reader);
// case "Polygon":
// readMulti=gjson.readPolygon(reader);
// case "MultiPolygon":
// readMulti=gjson.readMultiPolygon(reader);
// }
//
// feature.setAttribute("the_geom",readMulti);
feature.setAttribute("POIID",i);
writer.write();
}
writer.close();
ds.dispose();
map.put("status", "success");
map.put("message", shpPath);
}
catch(Exception e){
map.put("status", "failure");
map.put("message", e.getMessage());
e.printStackTrace();
}
return map;
} 是不是看上去很简单，是的就是这么简单。下面让我们来看下我们的CSV文件如何转化的吧的的的的.csv文件可以是甲骨文的MySQL的的的或者导出的文件。此时如果你从数据库中导出了CSV文件，但是又想把它生存的.SHP文件。此时这里的代码是不是又解了你的燃眉之急呢？不说了，直接上代码。
/**
* excel转shp
* @param xlsfile
* @param shppath
*/
public void excel2Shape(String xlsfile, String shppath) {
POIFSFileSystem fs;
HSSFWorkbook wb;
HSSFRow row;
try {
InputStream is = new FileInputStream(xlsfile);
fs = new POIFSFileSystem(is);
wb = new HSSFWorkbook(fs);
sheet = wb.getSheetAt(0);
//获取总列数
int colNum = sheet.getRow(0).getPhysicalNumberOfCells();
// 得到总行数
int rowNum = sheet.getLastRowNum();
List list = getExcelHeader();
//创建shape文件对象
File file = new File(shppath);
Map<String, Serializable> params = new HashMap<String, Serializable>();
params.put(ShapefileDataStoreFactory.URLP.key, file.toURI().toURL());
ShapefileDataStore ds = (ShapefileDataStore) new ShapefileDataStoreFactory().createNewDataStore(params);
//定义图形信息和属性信息
SimpleFeatureTypeBuilder tb = new SimpleFeatureTypeBuilder();
tb.setCRS(DefaultGeographicCRS.WGS84);
tb.setName("shapefile");
tb.add("the_geom", Point.class);
for (int i = 0; i < list.size(); i++) {
Map<String, Object> map = (Map<String, Object>) list.get(i);
tb.add(map.get("name").toString(), (Class) map.get("type"));
}
ds.createSchema(tb.buildFeatureType());
//设置编码
Charset charset = Charset.forName("GBK");
ds.setStringCharset(charset);
//设置Writer
FeatureWriter<SimpleFeatureType, SimpleFeature> writer = ds.getFeatureWriter(ds.getTypeNames()[0], Transaction.AUTO_COMMIT);
//写下一条
SimpleFeature feature = null;
for (int i = 1; i < rowNum; i++) {
row = sheet.getRow(i);
feature = writer.next();
Map mapLonLat = new HashMap();
for (int j = 0; j < colNum; j++) {
HSSFCell cell = row.getCell(j);
Map<String, Object> mapFields = (Map<String, Object>) list.get(j);
String fieldName = mapFields.get("name").toString();
feature.setAttribute(fieldName, getCellValue(cell));
if (fieldName.toLowerCase().equals("lon") || fieldName.toLowerCase().equals("lat")) {
mapLonLat.put(fieldName, getCellValue(cell));
}
}
feature.setAttribute("the_geom", new GeometryFactory().createPoint(new Coordinate((double) mapLonLat.get("lon"), (double) mapLonLat.get("lat"))));
}
writer.write();
writer.close();
ds.dispose();
} catch (Exception e) {
e.printStackTrace();
}
} 是不是很简单。我知道你们有的会问，上面的那个getFirstHeadWordChar（）方法里面是什么是吧。我都猜到了。
/**
* 提取第一个汉子/单词的首字母(大写)
*
* @param str
* @return
*/
public static String getFirstHeadWordChar(String str) {
if (isNull(str)) {
return "";
}
String convert = "";
char word = str.charAt(0);
// 提取汉字的首字母
String[] pinyinArray = PinyinHelper.toHanyuPinyinStringArray(word);
if (pinyinArray != null) {
convert += pinyinArray[0].charAt(0);
}
else {
convert += word;
}
convert = string2AllTrim(convert);
return convert.toUpperCase();
}
/**
* 提取每个汉字的首字母(大写)
*
* @param str
* @return
*/
public static String getPinYinHeadChar(String str) {
if (isNull(str)) {
return "";
}
String convert = "";
for (int j = 0; j < str.length(); j++) {
char word = str.charAt(j);
// 提取汉字的首字母
String[] pinyinArray = PinyinHelper.toHanyuPinyinStringArray(word);
if (pinyinArray != null) {
convert += pinyinArray[0].charAt(0);
}
else {
convert += word;
}
}
convert = string2AllTrim(convert);
return convert.toUpperCase();
}
/*
* 判断字符串是否为空
*/
public static boolean isNull(Object strData) {
if (strData == null || String.valueOf(strData).trim().equals("")) {
return true;
}
return false;
}
/**
* 去掉字符串包含的所有空格
*
* @param value
* @return
*/
public static String string2AllTrim(String value) {
if (isNull(value)) {
return "";
}
return value.trim().replace(" ", "");
}是不是很简单。上面是我写的一个工具类。哦，好像还掉了一点。上面还有一个文件写入的代码append2File（）和一个文件读取的方法getFileContent（）。
/**
* 文件写入
* @param jsonPath
* @param soure
*/
public void append2File(String jsonPath, String soure) {
// TODO Auto-generated method stub
File file = new File(jsonPath);
try {
OutputStream os = new FileOutputStream(file);
OutputStreamWriter osw = new OutputStreamWriter(os);
osw.write(soure);
osw.flush();
osw.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
/*
* 文件读取
* */
public String getFileContent(String jsonPath) {
File file = new File(jsonPath);
StringBuffer sb=new StringBuffer();
try {
InputStream out = new FileInputStream(file);
InputStreamReader reader=new InputStreamReader(out,"GBK");
while (reader.ready()) {
sb.append((char)reader.read());
}
out.close();
reader.close();
} catch (Exception e) {
// TODO: handle exception
}
return sb.toString();
}现在我们做GIS的项目。希望这些能帮助到一些人吧。后期我会更新一些有关openlayer的一些知识，感觉GIS还是蛮好玩。
再见了大家。拜拜
备注源码下载地址：https://download.youkuaiyun.com/download/yuwinter/10311544
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