SQLValueProcessor

chat2db-server/chat2db-plugins/chat2db-mysql/src/main/java/ai/chat2db/plugin/mysql/type/MysqlValueProcessorEnum.java

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+package ai.chat2db.plugin.mysql.type;
+
+import ai.chat2db.spi.SQLValueProcessor;
+import org.locationtech.jts.geom.Geometry;
+import org.locationtech.jts.io.WKBReader;
+
+import java.io.ByteArrayOutputStream;
+import java.io.InputStream;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+public enum MysqlValueProcessorEnum implements SQLValueProcessor {
+    GEOMETRY{
+        @Override
+        public String getSqlValueString(ResultSet rs, int index) throws SQLException {
+            try {
+                InputStream inputStream = rs.getBinaryStream(index);
+                Geometry dbGeometry = null;
+                if (inputStream != null) {
+
+                    //convert the stream to a byte[] array
+                    //so it can be passed to the WKBReader
+                    byte[] buffer = new byte[255];
+
+                    int bytesRead = 0;
+                    ByteArrayOutputStream baos = new ByteArrayOutputStream();
+                    while ((bytesRead = inputStream.read(buffer)) != -1) {
+                        baos.write(buffer, 0, bytesRead);
+                    }
+
+                    byte[] geometryAsBytes = baos.toByteArray();
+
+                    if (geometryAsBytes.length < 5) {
+                        throw new Exception("Invalid geometry inputStream - less than five bytes");
+                    }
+
+                    //first four bytes of the geometry are the SRID,
+                    //followed by the actual WKB.  Determine the SRID
+                    //here
+                    byte[] sridBytes = new byte[4];
+                    System.arraycopy(geometryAsBytes, 0, sridBytes, 0, 4);
+                    boolean bigEndian = (geometryAsBytes[4] == 0x00);
+
+                    int srid = 0;
+                    if (bigEndian) {
+                        for (int i = 0; i < sridBytes.length; i++) {
+                            srid = (srid << 8) + (sridBytes[i] & 0xff);
+                        }
+                    } else {
+                        for (int i = 0; i < sridBytes.length; i++) {
+                            srid += (sridBytes[i] & 0xff) << (8 * i);
+                        }
+                    }
+
+                    //use the JTS WKBReader for WKB parsing
+                    WKBReader wkbReader = new WKBReader();
+
+                    //copy the byte array, removing the first four
+                    //SRID bytes
+                    byte[] wkb = new byte[geometryAsBytes.length - 4];
+                    System.arraycopy(geometryAsBytes, 4, wkb, 0, wkb.length);
+                    dbGeometry = wkbReader.read(wkb);
+                    dbGeometry.setSRID(srid);
+                }
+                return dbGeometry.toString();
+            } catch (Exception e) {
+                return rs.getString(index);
+            }
+        }
+    };
+}

chat2db-server/chat2db-plugins/chat2db-mysql/src/main/java/ai/chat2db/plugin/mysql/value/MysqlValueProcessor.java

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+package ai.chat2db.plugin.mysql.value;
+
+import ai.chat2db.plugin.mysql.type.MysqlColumnTypeEnum;
+import ai.chat2db.plugin.mysql.type.MysqlValueProcessorEnum;
+import ai.chat2db.spi.jdbc.DefaultSQLValueProcessor;
+
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+/**
+ * @author: zgq
+ * @date: 2024年05月24日 21:02
+ */
+public class MysqlValueProcessor extends DefaultSQLValueProcessor {
+    /**
+     * @param rs
+     * @param index
+     * @return
+     * @throws SQLException
+     */
+    @Override
+    public String getSqlValueString(ResultSet rs, int index) throws SQLException {
+        Object obj = rs.getObject(index);
+        if (obj == null) {
+            return null;
+        }
+        String columnTypeName = rs.getMetaData().getColumnTypeName(index);
+        if (MysqlColumnTypeEnum.GEOMETRY.name().equalsIgnoreCase(columnTypeName)
+                || MysqlColumnTypeEnum.POINT.name().equalsIgnoreCase(columnTypeName)
+                || MysqlColumnTypeEnum.LINESTRING.name().equalsIgnoreCase(columnTypeName)
+                || MysqlColumnTypeEnum.POLYGON.name().equalsIgnoreCase(columnTypeName)
+                || MysqlColumnTypeEnum.MULTIPOINT.name().equalsIgnoreCase(columnTypeName)
+                || MysqlColumnTypeEnum.MULTILINESTRING.name().equalsIgnoreCase(columnTypeName)
+                || MysqlColumnTypeEnum.MULTIPOLYGON.name().equalsIgnoreCase(columnTypeName)
+                || MysqlColumnTypeEnum.GEOMETRYCOLLECTION.name().equalsIgnoreCase(columnTypeName)
+        ) {
+            return MysqlValueProcessorEnum.GEOMETRY.getSqlValueString(rs, index);
+        } else {
+            super.getSqlValueString(rs, index);
+        }
+        return null;
+    }
+
+}