用java创建一个文档管理器，可以在这个管理器中存储一些文档模板

A: 首先，需要设计一个文档类（Document）作为模板，并在文档管理器（DocumentManager）中管理该类的实例。具体实现可以参考以下代码：

public class Document {
    private String title;
    private String content;

    public Document(String title, String content) {
        this.title = title;
        this.content = content;
    }

    public String getTitle() {
        return title;
    }

    public String getContent() {
        return content;
    }

    // override toString method to display the document information
    @Override
    public String toString() {
        return title + ": " + content;
    }
}

public class DocumentManager {
    private List<Document> documents;

    public DocumentManager() {
        this.documents = new ArrayList<>();
    }

    public void addDocument(Document document) {
        documents.add(document);
    }

    public void removeDocument(Document document) {
        documents.remove(document);
    }

    public List<Document> getDocuments() {
        return Collections.unmodifiableList(documents);
    }
}

使用示例：

// create a document manager
DocumentManager manager = new DocumentManager();

// create some document templates
Document doc1 = new Document("Template 1", "This is document template 1.");
Document doc2 = new Document("Template 2", "This is document template 2.");

// add templates to the document manager
manager.addDocument(doc1);
manager.addDocument(doc2);

// get all templates in the document manager
List<Document> templates = manager.getDocuments();
System.out.println("All document templates:");
for (Document template : templates) {
    System.out.println(template);
}

// remove a template from the document manager
manager.removeDocument(doc1);

// get all templates in the document manager again
templates = manager.getDocuments();
System.out.println("All document templates after removing one template:");
for (Document template : templates) {
    System.out.println(template);
}

输出结果：

All document templates:
Template 1: This is document template 1.
Template 2: This is document template 2.
All document templates after removing one template:
Template 2: This is document template 2.