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authorMarc G. Fournier <scrappy@hub.org>1998-01-13 02:19:56 +0000
committerMarc G. Fournier <scrappy@hub.org>1998-01-13 02:19:56 +0000
commit06bad7807584351c2ab1cd544d677fa0ea087544 (patch)
treec17f9da61c34ca63d8f4e4ba56cf1980d6a62c13 /src/interfaces/jdbc/example/psql.java
parentc77c608aa2aba1d8b8e70f6d35371d09b48ff584 (diff)
downloadpostgresql-06bad7807584351c2ab1cd544d677fa0ea087544.tar.gz
postgresql-06bad7807584351c2ab1cd544d677fa0ea087544.zip
Oops...missed over half the patch :(
Diffstat (limited to 'src/interfaces/jdbc/example/psql.java')
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diff --git a/src/interfaces/jdbc/example/psql.java b/src/interfaces/jdbc/example/psql.java
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+package example;
+
+import java.io.*;
+import java.sql.*;
+import java.text.*;
+
+/**
+ * This example application demonstrates some of the drivers other features
+ * by implementing a simple psql replacement in Java.
+ *
+ */
+
+public class psql
+{
+ Connection db; // The connection to the database
+ Statement st; // Our statement to run queries with
+ DatabaseMetaData dbmd; // This defines the structure of the database
+
+ public psql(String args[]) throws ClassNotFoundException, FileNotFoundException, IOException, SQLException
+ {
+ String url = args[0];
+ String usr = args[1];
+ String pwd = args[2];
+
+ // Load the driver
+ Class.forName("postgresql.Driver");
+
+ // Connect to database
+ System.out.println("Connecting to Database URL = " + url);
+ db = DriverManager.getConnection(url, usr, pwd);
+
+ dbmd = db.getMetaData();
+ st = db.createStatement();
+
+ // This prints the backend's version
+ System.out.println("Connected to "+dbmd.getDatabaseProductName()+" "+dbmd.getDatabaseProductVersion());
+
+ System.out.println();
+
+ // This provides us the means of reading from stdin
+ StreamTokenizer input = new StreamTokenizer(new InputStreamReader(System.in));
+ input.resetSyntax();
+ input.slashSlashComments(true); // allow // as a comment delimiter
+ input.eolIsSignificant(false); // treat eol's as spaces
+ input.wordChars(32,126);
+ input.whitespaceChars(59,59);
+ input.quoteChar(39);
+
+ // Now the main loop.
+ int tt=0,lineno=1;
+ while(tt!=StreamTokenizer.TT_EOF) {
+ System.out.print("["+lineno+"] ");
+ System.out.flush();
+
+ // Here, we trap SQLException so they don't terminate the application
+ try {
+ if((tt=input.nextToken())==StreamTokenizer.TT_WORD) {
+ processLine(input.sval);
+ lineno++;
+ }
+ } catch(SQLException ex) {
+ System.out.println(ex.getMessage());
+ }
+ }
+
+ System.out.println("Now closing the connection");
+ st.close();
+ db.close();
+
+ }
+
+ /**
+ * This processes a statement
+ */
+ public void processLine(String line) throws SQLException
+ {
+ if(line.startsWith("\\")) {
+ processSlashCommand(line);
+ return;
+ }
+
+ boolean type = st.execute(line);
+ boolean loop=true;
+ while(loop) {
+ if(type) {
+ // A ResultSet was returned
+ ResultSet rs=st.getResultSet();
+ displayResult(rs);
+ } else {
+ int count = st.getUpdateCount();
+
+ if(count==-1) {
+ // This indicates nothing left
+ loop=false;
+ } else {
+ // An update count was returned
+ System.out.println("Updated "+st.getUpdateCount()+" rows");
+ }
+ }
+
+ if(loop)
+ type = st.getMoreResults();
+ }
+ }
+
+ /**
+ * This displays a result set.
+ * Note: it closes the result once complete.
+ */
+ public void displayResult(ResultSet rs) throws SQLException
+ {
+ ResultSetMetaData rsmd = rs.getMetaData();
+
+ // Print the result column names
+ int cols = rsmd.getColumnCount();
+ for(int i=1;i<=cols;i++)
+ System.out.print(rsmd.getColumnLabel(i)+(i<cols?"\t":"\n"));
+
+ // now the results
+ while(rs.next()) {
+ for(int i=1;i<=cols;i++) {
+ Object o = rs.getObject(i);
+ if(rs.wasNull())
+ System.out.print("{null}"+(i<cols?"\t":"\n"));
+ else
+ System.out.print(rs.getObject(i).toString()+(i<cols?"\t":"\n"));
+ }
+ }
+
+ // finally close the result set
+ rs.close();
+ }
+
+ /**
+ * This process / commands (for now just /d)
+ */
+ public void processSlashCommand(String line) throws SQLException
+ {
+ if(line.startsWith("\\d")) {
+
+ if(line.startsWith("\\d ")) {
+ // Display details about a table
+ String table=line.substring(3);
+ displayResult(dbmd.getColumns(null,null,table,"%"));
+ } else {
+ String types[] = null;
+ if(line.equals("\\d"))
+ types=allUserTables;
+ else if(line.equals("\\di"))
+ types=usrIndices;
+ else if(line.equals("\\dt"))
+ types=usrTables;
+ else if(line.equals("\\ds"))
+ types=usrSequences;
+ else if(line.equals("\\dS"))
+ types=sysTables;
+ else
+ throw new SQLException("Unsupported \\d command: "+line);
+
+ // Display details about all system tables
+ //
+ // Note: the first two arguments are ignored. To keep to the spec,
+ // you must put null here
+ //
+ displayResult(dbmd.getTables(null,null,"%",types));
+ }
+ } else
+ throw new SQLException("Unsupported \\ command: "+line);
+ }
+
+ private static final String allUserTables[] = {"TABLE","INDEX","SEQUENCE"};
+ private static final String usrIndices[] = {"INDEX"};
+ private static final String usrTables[] = {"TABLE"};
+ private static final String usrSequences[] = {"SEQUENCE"};
+ private static final String sysTables[] = {"SYSTEM TABLE","SYSTEM INDEX"};
+
+ /**
+ * Display some instructions on how to run the example
+ */
+ public static void instructions()
+ {
+ System.out.println("\nThis example shows how some of the other JDBC features work within the\ndriver. It does this by implementing a very simple psql equivalent in java.\nNot everything that psql does is implemented.\n");
+ System.out.println("Useage:\n java example.psql jdbc:postgresql:database user password [debug]\n\nThe debug field can be anything. It's presence will enable DriverManager's\ndebug trace. Unless you want to see screens of items, don't put anything in\nhere.");
+ System.exit(1);
+ }
+
+ /**
+ * This little lot starts the test
+ */
+ public static void main(String args[])
+ {
+ System.out.println("PostgreSQL psql example v6.3 rev 1\n");
+
+ if(args.length<3)
+ instructions();
+
+ // This line outputs debug information to stderr. To enable this, simply
+ // add an extra parameter to the command line
+ if(args.length>3)
+ DriverManager.setLogStream(System.err);
+
+ // Now run the tests
+ try {
+ psql test = new psql(args);
+ } catch(Exception ex) {
+ System.err.println("Exception caught.\n"+ex);
+ ex.printStackTrace();
+ }
+ }
+}