PostgreSQL+PostGIS 的使用
时间：2021-07-01 10:21:17
帮助过：2人阅读
wuyf;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
public class Wind
{
private Connection conn =
null;
public Connection getConn()
{
if (conn==
null)
{
try
{
Class.forName("org.postgresql.Driver"
);
String url = "jdbc:postgresql://localhost:5432/sde"
;
conn = DriverManager.getConnection(url, "sde" , "pwd"
);
conn.setAutoCommit(false);
}
catch(Exception e)
{
System.err.print(e);
}
}
return conn;
}
public ArrayList >
getWinds()
{
ArrayList > result =
new ArrayList >
();
if (
this.getConn()==
null )
return result;
try
{
String sql = "select *,ST_AsGeoJson(shape) from sde.wind"
;
Statement st =
this.getConn().createStatement();
st.setFetchSize(0
);
ResultSet rs =
st.executeQuery(sql);
while (rs.next())
{
HashMap map =
new HashMap ();
map.put("shape", rs.getString("ST_AsGeoJson"
));
map.put("velocity", rs.getString("velocity"
));
map.put("direction", rs.getString("direction"
));
result.add(map);
}
rs.close();
st.close();
}
catch(Exception e)
{
System.err.print(e);
}
return result;
}
public ArrayList >
getEffectZones()
{
ArrayList > result =
new ArrayList >
();
if (
this.getConn()==
null )
return result;
try
{
String sql = "select *,ST_AsGeoJson("
;
sql+= "ST_Buffer("
;
sql+= "ST_PolygonFromText("
;
sql+= "‘POLYGON((‘"
;
sql+= "||ST_X(shape)||‘ ‘||ST_Y(shape)||‘,‘"
;
sql+= "||ST_X(shape)+velocity*cos((direction+15)*PI()/180)/20||‘ ‘||ST_Y(shape)+velocity*sin((direction+15)*PI()/180)/20||‘,‘"
;
sql+= "||ST_X(shape)+velocity*cos((direction-15)*PI()/180)/20||‘ ‘||ST_Y(shape)+velocity*sin((direction-15)*PI()/180)/20||‘,‘"
;
sql+= "||ST_X(shape)||‘ ‘||ST_Y(shape)||‘))‘"
;
sql+= ")"
;
sql+= ", velocity/50"
;
sql+= ")"
;
sql+= ") "
;
sql+="from sde.wind"
;
Statement st =
this.getConn().createStatement();
st.setFetchSize(0
);
ResultSet rs =
st.executeQuery(sql);
while (rs.next())
{
HashMap map =
new HashMap ();
map.put("shape", rs.getString("ST_AsGeoJson"
));
map.put("velocity", rs.getString("velocity"
));
map.put("direction", rs.getString("direction"
));
result.add(map);
}
rs.close();
st.close();
}
catch(Exception e)
{
System.err.print(e);
}
return result;
}
}
PostgreSQL+PostGIS 的使用
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