第16章 - GeoServer集成开发
第16章 - GeoServer集成开发
16.1 GeoServer 与 GeoTools
16.1.1 架构关系
┌─────────────────────────────────────────────────────────────────────┐
│ GeoServer │
├─────────────────────────────────────────────────────────────────────┤
│ │
│ REST API Web Admin OGC Services │
│ ┌─────────┐ ┌─────────┐ ┌──────────────┐ │
│ │ REST │ │ Wicket │ │ WMS│WFS│WCS │ │
│ │ Module │ │ UI │ │ WMTS│CSW│WPS│ │
│ └────┬────┘ └────┬────┘ └──────┬───────┘ │
│ │ │ │ │
│ └────────────────┼────────────────────┘ │
│ │ │
│ ┌──────▼──────┐ │
│ │ Catalog │ │
│ │ API │ │
│ └──────┬──────┘ │
│ │ │
│ ┌─────────────────────┼─────────────────────┐ │
│ │ GeoTools │ │
│ │ DataStore │ Style │ Renderer │ CRS │ │
│ └───────────────────────────────────────────┘ │
│ │
└─────────────────────────────────────────────────────────────────────┘
16.1.2 GeoServer 插件开发
GeoServer 基于 GeoTools，开发 GeoServer 插件通常涉及：
- DataStore 插件：支持新的数据格式
- 处理插件：WPS 处理
- 输出格式插件：新的输出格式
- 服务插件：新的 OGC 服务
16.2 REST API 调用
16.2.1 Java 客户端
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.util.Base64;
public class GeoServerRESTClient {
private final String baseUrl;
private final HttpClient client;
private final String authHeader;
public GeoServerRESTClient(String baseUrl, String username, String password) {
this.baseUrl = baseUrl;
this.client = HttpClient.newHttpClient();
this.authHeader = "Basic " + Base64.getEncoder()
.encodeToString((username + ":" + password).getBytes());
}
// 获取工作空间列表
public String getWorkspaces() throws Exception {
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create(baseUrl + "/rest/workspaces.json"))
.header("Authorization", authHeader)
.GET()
.build();
HttpResponse<String> response = client.send(request,
HttpResponse.BodyHandlers.ofString());
return response.body();
}
// 获取图层列表
public String getLayers() throws Exception {
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create(baseUrl + "/rest/layers.json"))
.header("Authorization", authHeader)
.GET()
.build();
HttpResponse<String> response = client.send(request,
HttpResponse.BodyHandlers.ofString());
return response.body();
}
// 创建工作空间
public void createWorkspace(String name) throws Exception {
String json = "{\"workspace\":{\"name\":\"" + name + "\"}}";
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create(baseUrl + "/rest/workspaces"))
.header("Authorization", authHeader)
.header("Content-Type", "application/json")
.POST(HttpRequest.BodyPublishers.ofString(json))
.build();
HttpResponse<String> response = client.send(request,
HttpResponse.BodyHandlers.ofString());
if (response.statusCode() != 201) {
throw new RuntimeException("创建失败: " + response.body());
}
}
// 发布 Shapefile
public void publishShapefile(String workspace, String storeName,
File shpFile) throws Exception {
// 上传 ZIP 文件
byte[] zipContent = createZip(shpFile);
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create(baseUrl + "/rest/workspaces/" + workspace +
"/datastores/" + storeName + "/file.shp"))
.header("Authorization", authHeader)
.header("Content-Type", "application/zip")
.PUT(HttpRequest.BodyPublishers.ofByteArray(zipContent))
.build();
HttpResponse<String> response = client.send(request,
HttpResponse.BodyHandlers.ofString());
if (response.statusCode() != 201) {
throw new RuntimeException("发布失败: " + response.body());
}
}
private byte[] createZip(File shpFile) throws Exception {
// 创建包含 .shp, .shx, .dbf, .prj 的 ZIP
ByteArrayOutputStream baos = new ByteArrayOutputStream();
try (ZipOutputStream zos = new ZipOutputStream(baos)) {
String baseName = shpFile.getName().replace(".shp", "");
String[] extensions = {".shp", ".shx", ".dbf", ".prj"};
for (String ext : extensions) {
File f = new File(shpFile.getParent(), baseName + ext);
if (f.exists()) {
zos.putNextEntry(new ZipEntry(f.getName()));
Files.copy(f.toPath(), zos);
zos.closeEntry();
}
}
}
return baos.toByteArray();
}
}
16.2.2 配置样式
public class GeoServerStyleManager {
private final GeoServerRESTClient client;
public GeoServerStyleManager(GeoServerRESTClient client) {
this.client = client;
}
// 上传 SLD 样式
public void uploadStyle(String styleName, String sldContent) throws Exception {
// 先创建样式
HttpRequest createRequest = HttpRequest.newBuilder()
.uri(URI.create(client.baseUrl + "/rest/styles"))
.header("Authorization", client.authHeader)
.header("Content-Type", "application/vnd.ogc.sld+xml")
.POST(HttpRequest.BodyPublishers.ofString(
"<style><name>" + styleName + "</name><filename>" +
styleName + ".sld</filename></style>"))
.build();
// 上传 SLD 内容
HttpRequest uploadRequest = HttpRequest.newBuilder()
.uri(URI.create(client.baseUrl + "/rest/styles/" + styleName))
.header("Authorization", client.authHeader)
.header("Content-Type", "application/vnd.ogc.sld+xml")
.PUT(HttpRequest.BodyPublishers.ofString(sldContent))
.build();
// 执行请求...
}
// 为图层设置样式
public void setLayerStyle(String workspace, String layerName,
String styleName) throws Exception {
String json = "{\"layer\":{\"defaultStyle\":{\"name\":\"" +
styleName + "\"}}}";
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create(client.baseUrl + "/rest/layers/" +
workspace + ":" + layerName))
.header("Authorization", client.authHeader)
.header("Content-Type", "application/json")
.PUT(HttpRequest.BodyPublishers.ofString(json))
.build();
// 执行请求...
}
}
16.3 WPS 处理开发
16.3.1 创建 WPS 处理
import org.geotools.process.factory.DescribeParameter;
import org.geotools.process.factory.DescribeProcess;
import org.geotools.process.factory.DescribeResult;
import org.geotools.process.gs.GSProcess;
@DescribeProcess(
title = "Buffer Process",
description = "创建缓冲区"
)
public class BufferWPSProcess implements GSProcess {
@DescribeResult(name = "result", description = "缓冲区结果")
public SimpleFeatureCollection execute(
@DescribeParameter(name = "features", description = "输入要素")
SimpleFeatureCollection features,
@DescribeParameter(name = "distance", description = "缓冲区距离")
Double distance
) throws Exception {
SimpleFeatureType originalType = features.getSchema();
// 创建输出类型
SimpleFeatureTypeBuilder typeBuilder = new SimpleFeatureTypeBuilder();
typeBuilder.init(originalType);
typeBuilder.setName("buffered");
// 修改几何类型为 Polygon
typeBuilder.remove(originalType.getGeometryDescriptor().getLocalName());
typeBuilder.add("the_geom", Polygon.class);
SimpleFeatureType resultType = typeBuilder.buildFeatureType();
DefaultFeatureCollection result = new DefaultFeatureCollection();
SimpleFeatureBuilder builder = new SimpleFeatureBuilder(resultType);
try (SimpleFeatureIterator iter = features.features()) {
while (iter.hasNext()) {
SimpleFeature feature = iter.next();
Geometry geom = (Geometry) feature.getDefaultGeometry();
Geometry buffer = geom.buffer(distance);
builder.add(buffer);
for (int i = 0; i < feature.getAttributeCount(); i++) {
if (!(feature.getAttribute(i) instanceof Geometry)) {
builder.add(feature.getAttribute(i));
}
}
result.add(builder.buildFeature(null));
}
}
return result;
}
}
16.3.2 注册 WPS 处理
在 META-INF/services/org.geotools.process.ProcessFactory 文件中注册：
com.example.wps.BufferWPSProcessFactory
工厂类：
public class BufferWPSProcessFactory extends AnnotatedBeanProcessFactory {
public BufferWPSProcessFactory() {
super(
Text.text("Custom WPS Processes"),
"custom",
BufferWPSProcess.class
);
}
}
16.4 自定义 DataStore
16.4.1 DataStore 工厂
public class MyDataStoreFactory implements DataStoreFactorySpi {
public static final Param URL_PARAM = new Param(
"url", URL.class, "数据 URL", true);
@Override
public String getDisplayName() {
return "My Custom DataStore";
}
@Override
public String getDescription() {
return "自定义数据格式支持";
}
@Override
public Param[] getParametersInfo() {
return new Param[] { URL_PARAM };
}
@Override
public boolean canProcess(Map<String, ?> params) {
if (params.containsKey("url")) {
Object url = params.get("url");
if (url instanceof URL) {
return ((URL) url).toString().endsWith(".myformat");
}
}
return false;
}
@Override
public DataStore createDataStore(Map<String, ?> params) throws IOException {
URL url = (URL) params.get("url");
return new MyDataStore(url);
}
@Override
public DataStore createNewDataStore(Map<String, ?> params) throws IOException {
return createDataStore(params);
}
@Override
public boolean isAvailable() {
return true;
}
}
16.5 本章小结
本章介绍了 GeoServer 与 GeoTools 的集成开发：
-
架构关系
- GeoServer 基于 GeoTools
- 共享核心组件
-
REST API
- Java 客户端
- 工作空间和图层管理
- 样式配置
-
WPS 开发
- 创建处理类
- 注册工厂
-
DataStore 扩展
- 自定义数据格式
关键要点
- GeoServer 扩展遵循 GeoTools 接口
- REST API 提供完整的管理能力
- WPS 处理可重用 GeoTools 分析功能
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