com.github.datalking.common.env.MutablePropertySources Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of play-mvc Show documentation
simple mvc framework based on java servlet.
The newest version!
package com.github.datalking.common.env;

import com.github.datalking.util.Assert;
import com.github.datalking.util.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.Iterator;
import java.util.LinkedList;

/**
 * 保存多个PropertySource，核心是List
 *
 * @author yaoo on 5/28/18
 */
public class MutablePropertySources implements PropertySources {

    static final String NON_EXISTENT_PROPERTY_SOURCE_MESSAGE = "PropertySource named [%s] does not exist";
    static final String ILLEGAL_RELATIVE_ADDITION_MESSAGE = "PropertySource named [%s] cannot be added relative to itself";

    private final Logger logger = LoggerFactory.getLogger(this.getClass());

    private final LinkedList> propertySourceList = new LinkedList<>();

    public MutablePropertySources() {
    }

    /**
     * Create a new {@code MutablePropertySources} from the given propertySources
     * object, preserving the original order of contained {@code PropertySource} objects.
     */
    public MutablePropertySources(PropertySources propertySources) {
        this();
        for (PropertySource propertySource : propertySources) {
            this.addLast(propertySource);
        }
    }


    public boolean contains(String name) {
        return this.propertySourceList.contains(PropertySource.named(name));
    }

    public PropertySource get(String name) {
        int index = this.propertySourceList.indexOf(PropertySource.named(name));
        return index == -1 ? null : this.propertySourceList.get(index);
    }

    public Iterator> iterator() {
        return this.propertySourceList.iterator();
    }

    /**
     * Add the given property source object with highest precedence.
     */
    public void addFirst(PropertySource propertySource) {
        if (logger.isDebugEnabled()) {
            logger.debug(String.format("Adding [%s] PropertySource with highest search precedence",
                    propertySource.getName()));
        }
        removeIfPresent(propertySource);
        this.propertySourceList.addFirst(propertySource);
    }

    /**
     * Add the given property source object with lowest precedence.
     */
    public void addLast(PropertySource propertySource) {
        if (logger.isDebugEnabled()) {
            logger.debug(String.format("Adding [%s] PropertySource with lowest search precedence",
                    propertySource.getName()));
        }
        removeIfPresent(propertySource);
        this.propertySourceList.addLast(propertySource);
    }

    /**
     * Add the given property source object with precedence immediately higher
     * than the named relative property source.
     */
    public void addBefore(String relativePropertySourceName, PropertySource propertySource) {
        if (logger.isDebugEnabled()) {
            logger.debug(String.format("Adding [%s] PropertySource with search precedence immediately higher than [%s]",
                    propertySource.getName(), relativePropertySourceName));
        }
        assertLegalRelativeAddition(relativePropertySourceName, propertySource);
        removeIfPresent(propertySource);
        int index = assertPresentAndGetIndex(relativePropertySourceName);
        addAtIndex(index, propertySource);
    }

    /**
     * Add the given property source object with precedence immediately lower
     * than the named relative property source.
     */
    public void addAfter(String relativePropertySourceName, PropertySource propertySource) {
        if (logger.isDebugEnabled()) {
            logger.debug(String.format("Adding [%s] PropertySource with search precedence immediately lower than [%s]",
                    propertySource.getName(), relativePropertySourceName));
        }
        assertLegalRelativeAddition(relativePropertySourceName, propertySource);
        removeIfPresent(propertySource);
        int index = assertPresentAndGetIndex(relativePropertySourceName);
        addAtIndex(index + 1, propertySource);
    }

    /**
     * Return the precedence of the given property source, {@code -1} if not found.
     */
    public int precedenceOf(PropertySource propertySource) {
        return this.propertySourceList.indexOf(propertySource);
    }

    /**
     * Remove and return the property source with the given name, {@code null} if not found.
     *
     * @param name the name of the property source to find and remove
     */
    public PropertySource remove(String name) {
        if (logger.isDebugEnabled()) {
            logger.debug(String.format("Removing [%s] PropertySource", name));
        }
        int index = this.propertySourceList.indexOf(PropertySource.named(name));
        return index == -1 ? null : this.propertySourceList.remove(index);
    }

    /**
     * Replace the property source with the given name with the given property source object.
     *
     * @param name           the name of the property source to find and replace
     * @param propertySource the replacement property source
     * @throws IllegalArgumentException if no property source with the given name is present
     */
    public void replace(String name, PropertySource propertySource) {
        if (logger.isDebugEnabled()) {
            logger.debug(String.format("Replacing [%s] PropertySource with [%s]",
                    name, propertySource.getName()));
        }
        int index = assertPresentAndGetIndex(name);
        this.propertySourceList.set(index, propertySource);
    }

    /**
     * Return the number of {@link PropertySource} objects contained.
     */
    public int size() {
        return this.propertySourceList.size();
    }

    @Override
    public String toString() {
        String[] names = new String[this.size()];
        for (int i = 0; i < size(); i++) {
            names[i] = this.propertySourceList.get(i).getName();
        }
        return String.format("[%s]", StringUtils.arrayToCommaDelimitedString(names));
    }

    /**
     * Ensure that the given property source is not being added relative to itself.
     */
    protected void assertLegalRelativeAddition(String relativePropertySourceName, PropertySource propertySource) {
        String newPropertySourceName = propertySource.getName();
        Assert.isTrue(!relativePropertySourceName.equals(newPropertySourceName),
                String.format(ILLEGAL_RELATIVE_ADDITION_MESSAGE, newPropertySourceName));
    }

    /**
     * Remove the given property source if it is present.
     */
    protected void removeIfPresent(PropertySource propertySource) {
        if (this.propertySourceList.contains(propertySource)) {
            this.propertySourceList.remove(propertySource);
        }
    }

    /**
     * Add the given property source at a particular index in the list.
     */
    private void addAtIndex(int index, PropertySource propertySource) {
        removeIfPresent(propertySource);
        this.propertySourceList.add(index, propertySource);
    }

    /**
     * Assert that the named property source is present and return its index.
     *
     * @param name the {@linkplain PropertySource#getName() name of the property source}
     *             to find
     * @throws IllegalArgumentException if the named property source is not present
     */
    private int assertPresentAndGetIndex(String name) {
        int index = this.propertySourceList.indexOf(PropertySource.named(name));
        Assert.isTrue(index >= 0, String.format(NON_EXISTENT_PROPERTY_SOURCE_MESSAGE, name));
        return index;
    }

}