Example usage for java.lang.reflect Constructor newInstance

List of usage examples for java.lang.reflect Constructor newInstance

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Introduction

In this page you can find the example usage for java.lang.reflect Constructor newInstance.

Prototype

@CallerSensitive
@ForceInline 
public T newInstance(Object... initargs) throws InstantiationException, IllegalAccessException,
        IllegalArgumentException, InvocationTargetException

Source Link

Document

Uses the constructor represented by this Constructor object to create and initialize a new instance of the constructor's declaring class, with the specified initialization parameters.

Usage

From source file:io.coala.factory.ClassUtil.java

/**
 * @param returnType the type of the stored property value
 * @param args the arguments for construction
 * @return the property value's class instantiated
 * @throws CoalaException if the property's value is no instance of
 *             valueClass// w  w  w. j a va2s. com
 */
@SuppressWarnings("unchecked")
public static <T> T instantiate(final Class<T> returnType, final Object... args) throws CoalaException {
    if (returnType == null)
        throw CoalaExceptionFactory.VALUE_NOT_SET.create("returnType");

    final Class<?>[] argTypes = new Class<?>[args.length];
    for (int i = 0; i < args.length; i++)
        argTypes[i] = args[i] == null ? null : args[i].getClass();

    for (Constructor<?> constructor : returnType.getConstructors()) {
        final Class<?>[] paramTypes = constructor.getParameterTypes();
        if (paramTypes.length != args.length) // different argument count,
        // try next constructor
        {
            continue;
        }

        boolean match = true;
        for (int i = 0; match && i < paramTypes.length; i++) {
            if (args[i] == null && !paramTypes[i].isPrimitive())
                argTypes[i] = paramTypes[i];
            else if (!isAssignableFrom(paramTypes[i], argTypes[i]))
                match = false;
        }

        if (!match) // no matching parameter types, try next constructor
        {
            continue;
        }

        try {
            return (T) constructor.newInstance(args);
        } catch (final InvocationTargetException exception) {
            // exception caused by the constructor itself, pass cause thru
            throw exception.getCause() instanceof CoalaException ? (CoalaException) exception.getCause()
                    : CoalaExceptionFactory.INCONSTRUCTIBLE.create(exception, returnType,
                            Arrays.asList(argTypes));
        } catch (final Exception exception) {
            throw CoalaExceptionFactory.INCONSTRUCTIBLE.create(exception, returnType, Arrays.asList(argTypes));
        }
    }
    throw CoalaExceptionFactory.INCONSTRUCTIBLE.create(returnType, Arrays.asList(argTypes));
}

From source file:com.bstek.dorado.web.servlet.ServletContextResourceLoader.java

public ServletContextResourceLoader(ServletContext servletContext) {
    this.servletContext = servletContext;
    String resourceLoaderClass = servletContext.getInitParameter("resourceLoaderClass");
    if (StringUtils.isNotEmpty(StringUtils.trim(resourceLoaderClass))) {
        ConsoleUtils.outputLoadingInfo("[resourceLoaderClass=" + resourceLoaderClass + "]");

        try {/*  ww  w  . j a va2 s .  co m*/
            @SuppressWarnings("unchecked")
            Class<ResourceLoader> type = ClassUtils.forName(resourceLoaderClass);
            Constructor<ResourceLoader> constr = type.getConstructor(new Class[] { ClassLoader.class });
            resourceLoader = constr.newInstance(new Object[] { getClass().getClassLoader() });
        } catch (Exception e) {
            logger.error(e, e);
        }
    }
}

From source file:marshalsec.gadgets.CommonsConfiguration.java

@Args(minArgs = 2, args = { "codebase", "class" }, defaultArgs = { MarshallerBase.defaultCodebase,
        MarshallerBase.defaultCodebaseClass })
@Primary/*w w w  . jav  a2  s. c  om*/
default Object makeConfigurationMap(UtilFactory uf, String[] args) throws Exception {
    Object jc = makeConfiguration(uf, args);
    Class<?> cl = Class.forName("org.apache.commons.configuration.ConfigurationMap");
    Constructor<?> cons = cl.getDeclaredConstructor(Configuration.class);
    cons.setAccessible(true);
    return uf.makeHashCodeTrigger(cons.newInstance(jc));
}

From source file:it.sample.parser.domain.TipologiaRapporto.java

/**
 * Restituisce una istanza della classe.
 *///  w  ww. j a  v a2 s.  c  o  m
public Rapporto newInstance(Rapporto rapporto) {
    try {
        Class<?>[] intArgsClass = new Class[] { Filiale.class, String.class, String.class };
        Object[] intArgs = new Object[] { rapporto.getFiliale(), rapporto.getCategoria(),
                rapporto.getNumeroRapporto() };
        Constructor<? extends Rapporto> constructor = clazz.getConstructor(intArgsClass);
        return Rapporto.class.cast(constructor.newInstance(intArgs));
    } catch (Exception e) {
        throw new UnsupportedOperationException(
                clazz.getName() + " non espone un costruttore privo di argomenti.");
    }
}

From source file:javazoom.jlgui.player.amp.playlist.PlaylistFactory.java

/**
 * Returns Playlist instantied from full qualified class name.
 *///from   w  w  w  .  j a v a  2s.com
public Playlist getPlaylist() {
    if (_playlistInstance == null) {
        String classname = _config.getPlaylistClassName();
        boolean interfaceFound = false;
        try {
            Class aClass = Class.forName(classname);
            Class superClass = aClass;
            // Looking for Playlist interface implementation.
            while (superClass != null) {
                Class[] interfaces = superClass.getInterfaces();
                for (int i = 0; i < interfaces.length; i++) {
                    if ((interfaces[i].getName()).equals("javazoom.jlgui.player.amp.playlist.Playlist")) {
                        interfaceFound = true;
                        break;
                    }
                }
                if (interfaceFound == true)
                    break;
                superClass = superClass.getSuperclass();
            }
            if (interfaceFound == false) {
                log.error("Error : Playlist implementation not found in " + classname + " hierarchy");
            } else {
                Class[] argsClass = new Class[] {};
                Constructor c = aClass.getConstructor(argsClass);
                _playlistInstance = (Playlist) (c.newInstance(null));
                log.info(classname + " loaded");
            }
        } catch (Exception e) {
            log.error("Error : " + classname + " : " + e.getMessage());
        }
    }
    return _playlistInstance;
}

From source file:com.xpn.xwiki.plugin.charts.plots.AreaPlotFactory.java

public Plot create(DataSource dataSource, ChartParams params) throws GenerateException, DataSourceException {
    Class rendererClass = params.getClass(ChartParams.RENDERER);
    if (rendererClass == null || XYItemRenderer.class.isAssignableFrom(rendererClass)) {
        XYItemRenderer renderer;//from  w w w.  jav  a  2  s  .  co m
        if (rendererClass != null) {
            try {
                Constructor ctor = rendererClass.getConstructor(new Class[] {});
                renderer = (XYItemRenderer) ctor.newInstance(new Object[] {});
            } catch (Throwable e) {
                throw new GenerateException(e);
            }
        } else {
            renderer = new XYAreaRenderer();
        }
        ChartCustomizer.customizeXYItemRenderer(renderer, params);

        return XYPlotFactory.getInstance().create(dataSource, renderer, params);
    } else if (CategoryItemRenderer.class.isAssignableFrom(rendererClass)) {
        CategoryItemRenderer renderer;
        if (rendererClass != null) {
            try {
                Constructor ctor = rendererClass.getConstructor(new Class[] {});
                renderer = (CategoryItemRenderer) ctor.newInstance(new Object[] {});
            } catch (Throwable e) {
                throw new GenerateException(e);
            }
        } else {
            renderer = new AreaRenderer();
        }
        ChartCustomizer.customizeCategoryItemRenderer(renderer, params);

        return CategoryPlotFactory.getInstance().create(dataSource, renderer, params);
    } else {
        throw new GenerateException("Incompatible renderer class: " + rendererClass);
    }
}

From source file:com.xpn.xwiki.plugin.charts.plots.BarPlotFactory.java

public Plot create(DataSource dataSource, ChartParams params) throws GenerateException, DataSourceException {
    Class rendererClass = params.getClass(ChartParams.RENDERER);
    if (rendererClass == null || CategoryItemRenderer.class.isAssignableFrom(rendererClass)) {
        CategoryItemRenderer renderer;/* w  w  w. j  ava  2  s  .c o  m*/
        if (rendererClass != null) {
            try {
                Constructor ctor = rendererClass.getConstructor(new Class[] {});
                renderer = (CategoryItemRenderer) ctor.newInstance(new Object[] {});
            } catch (Throwable e) {
                throw new GenerateException(e);
            }
        } else {
            renderer = new BarRenderer();
        }
        return CategoryPlotFactory.getInstance().create(dataSource, renderer, params);
    } else if (XYItemRenderer.class.isAssignableFrom(rendererClass)) {
        XYItemRenderer renderer;
        if (rendererClass != null) {
            try {
                Constructor ctor = rendererClass.getConstructor(new Class[] {});
                renderer = (XYItemRenderer) ctor.newInstance(new Object[] {});
            } catch (Throwable e) {
                throw new GenerateException(e);
            }
        } else {
            renderer = new XYBarRenderer(); // will never run
        }
        ChartCustomizer.customizeXYItemRenderer(renderer, params);

        return XYPlotFactory.getInstance().create(dataSource, renderer, params);
    } else {
        throw new GenerateException("Incompatible renderer class: " + rendererClass);
    }
}

From source file:it.cnr.icar.eric.client.admin.AdminShellFactory.java

/**
* Creates the instance of the pluginClass
*//*from ww  w .ja  v a2 s  .  c o m*/
private Object createPluginInstance(String pluginClass) throws Exception {
    Object plugin = null;

    log.debug("adminShellClass = " + pluginClass);

    Class<?> theClass = Class.forName(pluginClass);

    //try to invoke constructor using Reflection,
    //if this fails then try invoking getInstance()
    try {
        Constructor<?> constructor = theClass.getConstructor((java.lang.Class[]) null);
        plugin = constructor.newInstance(new Object[0]);
    } catch (Exception e) {
        log.warn(rb.getString(AdminShell.ADMIN_SHELL_RESOURCES_PREFIX + "noAccessibleConstructor"));

        Method factory = theClass.getDeclaredMethod("getInstance", (java.lang.Class[]) null);
        plugin = factory.invoke(null, new Object[0]);
    }

    return plugin;
}

From source file:net.joinedminds.masserr.util.IdentifiableBeanConverter.java

@Override
public Object convert(Class type, Object value) {
    if (type.isAssignableFrom(value.getClass())) {
        return value;
    }// w  w w .j av  a2s  . c o  m
    Constructor constructor;
    try {
        try {
            constructor = type.getConstructor(value.getClass());
            return constructor.newInstance(value);
        } catch (NoSuchMethodException e) {
            try {
                constructor = type.getConstructor(String.class);
                return constructor.newInstance(value.toString());
            } catch (NoSuchMethodException e1) {
                throw new ConversionException("Could not find single parameter constructor.", e1);
            }
        }
    } catch (Exception e) {
        throw new ConversionException("Could not construct " + type.getName(), e);
    }
}

From source file:com.xpn.xwiki.plugin.charts.plots.PiePlotFactory.java

public Plot create(DataSource dataSource, ChartParams params) throws GenerateException, DataSourceException {
    DefaultPieDataset dataset = new DefaultPieDataset();
    String dataSeries = params.getString(ChartParams.SERIES);
    if (dataSeries.equals("columns")) {
        for (int row = 0; row < dataSource.getRowCount(); row++) {
            if (dataSource.hasHeaderColumn()) {
                String category = dataSource.getHeaderColumnValue(row);
                dataset.setValue(category, dataSource.getCell(row, 0));
            } else {
                dataset.setValue("Category " + (row + 1), dataSource.getCell(row, 0));
            }//from   www  .j  a  v a 2s .  co m
        }
    } else if (dataSeries.equals("rows")) {
        for (int column = 0; column < dataSource.getColumnCount(); column++) {
            if (dataSource.hasHeaderRow()) {
                String category = dataSource.getHeaderRowValue(column);
                dataset.setValue(category, dataSource.getCell(0, column));
            } else {
                dataset.setValue("Category " + (column + 1), dataSource.getCell(0, column));
            }
        }
    } else {
        throw new GenerateException("Invalid series parameter:" + dataSeries);
    }

    Class plotClass = params.getClass(ChartParams.RENDERER);
    PiePlot plot;
    if (plotClass != null) {
        try {
            Constructor ctor = plotClass.getConstructor(new Class[] { PieDataset.class });
            plot = (PiePlot) ctor.newInstance(new Object[] { dataset });
        } catch (Throwable e) {
            throw new GenerateException(e);
        }
    } else {
        plot = new PiePlot(dataset);
    }
    ChartCustomizer.customizePiePlot(plot, params);
    return plot;
}