package org.geotools.renderer;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.geom.AffineTransform;
import java.util.Map;
import org.geotools.geometry.jts.ReferencedEnvelope;
import org.geotools.map.MapContent;
import org.locationtech.jts.geom.Envelope;
public interface GTRenderer {
    public void stopRendering();
    public void addRenderListener(RenderListener listener);
    public void removeRenderListener(RenderListener listener);
    public void setJava2DHints(RenderingHints hints);
    public RenderingHints getJava2DHints();
    public void setRendererHints(Map<?, ?> hints);
    public Map<Object, Object> getRendererHints();
    public void setMapContent(MapContent mapContent);
    public MapContent getMapContent();
    public void paint(Graphics2D graphics, Rectangle paintArea, AffineTransform worldToScreen);
    public void paint(Graphics2D graphics, Rectangle paintArea, Envelope mapArea);
    public void paint(Graphics2D graphics, Rectangle paintArea, ReferencedEnvelope mapArea);
    public void paint( Graphics2D graphics,Rectangle paintArea,Envelope mapArea,AffineTransform worldToScreen);
    public void paint(Graphics2D graphics, Rectangle paintArea,ReferencedEnvelope mapArea,AffineTransform worldToScreen);
}

 /** The thread pool used to submit the painter workers. */
private ExecutorService threadPool;
private PainterThread painterThread;

ExecutorService localThreadPool = threadPool;
boolean localPool = false;
if (localThreadPool == null) {
     localThreadPool = Executors.newSingleThreadExecutor();
     localPool = true;
}
Future painterFuture = localThreadPool.submit(painterThread);
List<CompositingGroup> compositingGroups = null;

public void saveImage(final MapContent map, final String file, final int imageWidth) {
    GTRenderer renderer = new StreamingRenderer();
    renderer.setMapContent(map);
    Rectangle imageBounds = null;
    ReferencedEnvelope mapBounds = null;
    try {
        mapBounds = map.getMaxBounds();
        double heightToWidth = mapBounds.getSpan(1) / mapBounds.getSpan(0);
        imageBounds = new Rectangle(
                0, 0, imageWidth, (int) Math.round(imageWidth * heightToWidth));
    } catch (Exception e) {
        // failed to access map layers
        throw new RuntimeException(e);
    }
    BufferedImage image = new BufferedImage(imageBounds.width, imageBounds.height, BufferedImage.TYPE_INT_RGB);
    Graphics2D gr = image.createGraphics();
    gr.setPaint(Color.WHITE);
    gr.fill(imageBounds);
    try {
        renderer.paint(gr, imageBounds, mapBounds);
        File fileToSave = new File(file);
        ImageIO.write(image, "jpeg", fileToSave);
    } catch (IOException e) {
        throw new RuntimeException(e);
    }
}

<dependency>
	<groupId>org.geotools</groupId>
	<artifactId>gt-referencing</artifactId>
	<version>${geotools.version}</version>
</dependency>
<dependency>
	<groupId>org.geotools</groupId>
	<artifactId>gt-epsg-hsql</artifactId>
	<version>${geotools.version}</version>
</dependency>
<dependency>
	<groupId>org.geotools</groupId>
	<artifactId>gt-epsg-extension</artifactId>
	<version>${geotools.version}</version>
</dependency>

private Style createStyleFromSld(String uri)
			throws XPathExpressionException, IOException, SAXException, ParserConfigurationException {
		DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
		DocumentBuilder db = dbf.newDocumentBuilder();
		Document xmlDocument = db.parse(uri);
		XPath xPath = XPathFactory.newInstance().newXPath();
		String version = xPath.compile("/StyledLayerDescriptor/@version").evaluate(xmlDocument);
		Configuration sldConf;
		if (version != null && version.startsWith("1.1")) {
			sldConf = new org.geotools.sld.v1_1.SLDConfiguration();
		} else {
			sldConf = new org.geotools.sld.SLDConfiguration();
		}
		StyledLayerDescriptor sld = (StyledLayerDescriptor) new org.geotools.xsd.DOMParser(sldConf, xmlDocument)
				.parse();
		NamedLayer l = (NamedLayer) sld.getStyledLayers()[0];
		Style style = l.getStyles()[0];
		return style;
}

/**
* 添加shp文件
* 
* @param shpPath
*/
@SuppressWarnings("deprecation")
public void addShapeLayer(String shpPath, String sldPath) {
	try {
		File file = new File(shpPath);
		ShapefileDataStore shpDataStore = null;
		shpDataStore = new ShapefileDataStore(file.toURL());
		// 設(shè)置編碼
		Charset charset = Charset.forName("GBK");
		shpDataStore.setCharset(charset);
		String typeName = shpDataStore.getTypeNames()[0];
		SimpleFeatureSource featureSource = null;
		featureSource = shpDataStore.getFeatureSource(typeName);
		// SLD的方式
		Style style = null;
		try {
			style = createStyleFromSld(sldPath);
		} catch (Exception e) {
		}
		Layer layer = new FeatureLayer(featureSource, style);
		map.addLayer(layer);
	} catch (Exception e) {
		e.printStackTrace();
	}
}

/**
* 根據(jù)四至、長、寬獲取地圖內(nèi)容，并生成圖片
* 
* @param paras
* @param imgPath
*/
public void getMapContent(Map<String, Object> paras, String imgPath) {
	try {
		double[] bbox = (double[]) paras.get("bbox");
		double x1 = bbox[0], y1 = bbox[1], x2 = bbox[2], y2 = bbox[3];
		int width = (int) paras.get("width"), height = (int) paras.get("height");
		// 設(shè)置輸出范圍
		CoordinateReferenceSystem crs = DefaultGeographicCRS.WGS84;
		// CoordinateReferenceSystem crs = CRS.decode("EPSG:4326");
		ReferencedEnvelope mapArea = new ReferencedEnvelope(x1, x2, y1, y2, crs);
		// 初始化渲染器
		StreamingRenderer sr = new StreamingRenderer();
		sr.setMapContent(map);
		// 初始化輸出圖像
		BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
		Graphics g = bi.getGraphics();
		((Graphics2D) g).setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
		((Graphics2D) g).setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,
					RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
		Rectangle rect = new Rectangle(0, 0, width, height);
		// 繪制地圖
		sr.paint((Graphics2D) g, rect, mapArea);
		// 將BufferedImage變量寫入文件中。
		ImageIO.write(bi, "png", new File(imgPath));
	} catch (Exception e) {
		e.printStackTrace();
	}
}

public static void main(String[] args) {
		long start = System.currentTimeMillis();
		Shp2Image shp2img = new Shp2Image();
		String shpPath = "F:/wzh_workspace_20210320/geotools-fx/src/main/resources/maps/countries.shp";
		String sldPath = "F:/wzh_workspace_20210320/geotools-fx/src/main/resources/maps/countries1.1.0-2.sld";
		String imgPath = "D:/countries0819-美國.png";
		Map<String, Object> paras = new HashMap<String, Object>();
		double[] bbox_usa = new double[] { -145.40999, 9.93976, -65.062300,81.12722 };
		paras.put("bbox", bbox_usa);
		paras.put("width", 1020);
		paras.put("height", 800);
		shp2img.addShapeLayer(shpPath, sldPath);
		shp2img.getMapContent(paras, imgPath);
		System.out.println("縮略圖生成完成，共耗時" + (System.currentTimeMillis() - start) + "ms");
}