社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 9078阅读
  • 0回复

http断点续传简单实现(java)

发帖
8
铜板
1641
人品值
95
贡献值
0
交易币
0
好评度
8
信誉值
0
金币
0
所在楼道
/* ]UtfI  
**SiteFileFetch.java !CJh6X !  
*/ B,2oA]W"S  
package NetFox; mmN!=mf*  
import java.io.*; ;nzzt~aCC  
import java.net.*; PWavq?SR  
],!7S"{97  
w;e42.\  
public class SiteFileFetch extends Thread { e}F1ZJz  
vvWje:H  
x{GKz#  
SiteInfoBean siteInfoBean = null; //文件信息Bean Kx8>  
long[] nStartPos; //开始位置 gb_r <j:w  
long[] nEndPos; //结束位置 E{):z g  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 etcpto=Mo  
long nFileLength; //文件长度 8`I/\8;H'p  
boolean bFirst = true; //是否第一次取文件 `~~.0QC  
boolean bStop = false; //停止标志 1[? xU:;9  
File tmpFile; //文件下载的临时信息 U};~ff+  
DataOutputStream output; //输出到文件的输出流 "Uk "  
)/32sz]~  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ZvQ~K(3  
public SiteFileFetch(SiteInfoBean bean) throws IOException Iu3*`H  
{ F<W`zQ46  
siteInfoBean = bean; #b^x!lR  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); e!eUgD  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); d]fo>[%Xr  
if(tmpFile.exists ())  Sj,>O:p  
{ HU~,_m  
bFirst = false; AK$h S M  
read_nPos(); ~s$ jiA1  
} JPs R7f  
else ZUkrJ'  
{ PO$ OXw  
nStartPos = new long[bean.getNSplitter()]; +{eZ@  
nEndPos = new long[bean.getNSplitter()]; KNI* :  
} I;=HXL  
8!{;yz  
4>JDo,AWy  
D&)w =qIu  
} 1\hh,s  
P&6hk6#  
Rt%3\?rf  
public void run() E0SP  
{ wZAY0@pA  
//获得文件长度 I: j!A  
//分割文件 NWN Pq"  
//实例FileSplitterFetch G!%Cc0d"7  
//启动FileSplitterFetch线程 G $P|F6  
//等待子线程返回 nVSuvq|S  
try{ H#Aar  
if(bFirst) l^LYSZg'R8  
{ QH) uh"  
nFileLength = getFileSize(); /4Df 'd  
if(nFileLength == -1) 5O7 x4bY  
{ y4^w8'%MC  
System.err.println("File Length is not known!"); \G+uK:PC,  
} =Wgz\uGJ  
else if(nFileLength == -2) 31FQ=(K  
{ #iZ%CY\  
System.err.println("File is not access!"); ^Z6N&s#6  
} $<]G#&F   
else C>A*L4c]F  
{ _QS+{  
for(int i=0;i<nStartPos.length;i++) @P$_2IU"  
{ yjq~O~  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); .lcI"%>  
} ox}LC, !  
for(int i=0;i<nEndPos.length-1;i++) MO1t 0Myc  
{ ;Wo\MN  
nEndPos = nStartPos[i+1]; +!'rw D  
} + A=*C  
nEndPos[nEndPos.length-1] = nFileLength; .b3c n  
} b `TA2h  
} Q\!0V@$  
@D'NoA@1A  
c~bTK" u  
//启动子线程 =}8:zO 2'{  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;X9nYH  
for(int i=0;i<nStartPos.length;i++) f{[] m(X;  
{ ,j'>}'wG)  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N1pw*<&  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \nX5 $[  
nStartPos,nEndPos,i); m4 :|  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0\Q/$#3  
fileSplitterFetch.start(); cTq}H_hC  
} Zy<gA >  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s={jwI50  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); A.D@21py  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", e2P ds`  
nEndPos = " + nFileLength); H7I&Ky  
// fileSplitterFetch[nPos.length-1].start(); @$e!|.{1q  
szDd!(&pv  
L{2KK]IF  
//等待子线程结束 3T<aGW1  
//int count = 0; RV&=B%w+  
//是否结束while循环 $_u9Y!  
boolean breakWhile = false; 7*a']W{aJ  
i6.HR?n  
9"jhS0M  
while(!bStop) o'`:$ (  
{ ipIexv1/S  
write_nPos(); :*/'W5iM  
Utility.sleep(500); 1R e5)Y:i  
breakWhile = true; /W vgC)  
8 <~E;:  
LH" CIL2  
for(int i=0;i<nStartPos.length;i++) ~zcHpxO^W  
{ d/m.VnW  
if(!fileSplitterFetch.bDownOver) IwR/4LYI  
{ #y?iUv  
breakWhile = false; =Eh~ wm  
break; sNF[-,a  
} Kc%GxD`  
} 3fb"1z#  
if(breakWhile) pow.@  
break; 5*n3*rbU:  
v&8%t 7|  
-9f> rH\3  
//count++; a%fMf[Fu  
//if(count>4) j3J\%7^i  
// siteStop(); TsvF~Gdp  
} (;Ad:!9{  
DO^K8~]  
R)<PCe`vf  
System.err.println("文件下载结束!"); +@ j@#~=K  
} JF+E.-fy$  
catch(Exception e){e.printStackTrace ();} )[c@5zy~*  
} ^e 1Ux  
kt0ma/QpP  
:B(vk3;U!  
//获得文件长度 \'BA}v &/  
public long getFileSize() ;:%*h2  
{ zFq8xw  
int nFileLength = -1; c^?+"7oO0  
try{ B9&$sTAB  
URL url = new URL(siteInfoBean.getSSiteURL()); $U]KIHb  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P>i!f!o*I  
httpConnection.setRequestProperty("User-Agent","NetFox"); nKO4o8js{{  
D=0^" 7K  
m"r=p  
int responseCode=httpConnection.getResponseCode(); ?_VoO  
if(responseCode>=400) 4$wn8!x2|  
{ ^`MGlI}   
processErrorCode(responseCode); f\{ynC2m  
return -2; //-2 represent access is error -%g$~MZ?'  
} 5g$]ou  
}%@q; "9`  
dpTeF`N  
String sHeader; d hp-XIA;  
FthrI  
h3<L,Olp  
for(int i=1;;i++) ?|`Ba-  
{ n'42CE  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J'=iEI  
//Utility.log(in.readLine()); hA6D*8oXD  
sHeader=httpConnection.getHeaderFieldKey(i); #ox &=MY  
if(sHeader!=null) RdirEH *H  
{ 8vK$]e36  
if(sHeader.equals("Content-Length")) Y]33:c_;Mo  
{ ^qro0]"LD  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (:spA5  
break; G%RL8HU  
} &Oxf^x["]  
} 3om_Z/k  
else +'@j~\>^yJ  
break; nc.(bb),  
} 2jUEL=+Y  
} FD+y?UF  
catch(IOException e){e.printStackTrace ();} 5r-OE-U{  
catch(Exception e){e.printStackTrace ();} .:nV^+)  
hbOyrjan x  
NhgzU+)+  
Utility.log(nFileLength); L2jjkyX]  
)yj:P  
GlPd)m`  
return nFileLength; xX5EhVR   
} gI /#7Cr  
_?YP0GpU  
3R=R k  
//保存下载信息(文件指针位置) I=DvP;!  
private void write_nPos() 3`mM0,fY  
{ G""L1?  
try{ +pefk+  
output = new DataOutputStream(new FileOutputStream(tmpFile)); vK10p)ZV  
output.writeInt(nStartPos.length); 9bxBm  
for(int i=0;i<nStartPos.length;i++) e-`=?tct  
{ Pcs62aE  
// output.writeLong(nPos); @N%/v*  
output.writeLong(fileSplitterFetch.nStartPos); '@WpJ{]A  
output.writeLong(fileSplitterFetch.nEndPos); 'PBuf:9lN  
} z K+C&X  
output.close(); I/HcIBJ  
} jMP!/t :w  
catch(IOException e){e.printStackTrace ();} w9W0j  
catch(Exception e){e.printStackTrace ();} 0?0$6F  
} .GM}3(1fX`  
f0h^ULd  
RaBq@r*(  
//读取保存的下载信息(文件指针位置) t V:oBT*  
private void read_nPos() $}TK ,/W  
{ Xe J|Z)qZ  
try{ `-J$7)d@  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); WYayr1  
int nCount = input.readInt(); dZ"B6L!^(  
nStartPos = new long[nCount]; itpljh  
nEndPos = new long[nCount]; A{QXzoWkg0  
for(int i=0;i<nStartPos.length;i++) ]5_6m;g  
{ I.qP$j  
nStartPos = input.readLong(); ?vd_8C2B  
nEndPos = input.readLong(); y. A]un1  
} $UX^$gG  
input.close(); pT ;{05  
} .vm.g=-q  
catch(IOException e){e.printStackTrace ();} (0c L! N;;  
catch(Exception e){e.printStackTrace ();} bY>JLRQJ-  
} ~ZN]2}  
O*:8gu'Y2  
RhPEda2  
private void processErrorCode(int nErrorCode) :9=J=G*  
{ Q 6)5*o8n  
System.err.println("Error Code : " + nErrorCode); L( B(x>w  
} 33*NgQ;&~'  
i=ztWKwKf  
>,#7 3u#  
//停止文件下载 ,];4+&|8kW  
public void siteStop() [&B}{6wry  
{ @=0O' XM  
bStop = true; &M5_G$5n  
for(int i=0;i<nStartPos.length;i++) eKT'd#o2R  
fileSplitterFetch.splitterStop(); -j<g}IG  
}p <p(  
+I9+L6>UR  
} i,h)  
} eLd7|*|  
//负责部分文件的抓取 4YmN3i  
**FileSplitterFetch.java ^UJ#YRzi  
*/ `"#0\Wh  
package NetFox; zq?Iwyo  
;Bs^+R7  
NETji:d  
import java.io.*; (K}Md~  
import java.net.*; qOi3`6LCV  
4wa8Vw`  
bktw?{h  
public class FileSplitterFetch extends Thread { Mb2rHUr  
J(s%"d  
51Nh"JTy  
String sURL; //File URL SjZ?keKZ  
long nStartPos; //File Snippet Start Position S(b5Gj/Kd  
long nEndPos; //File Snippet End Position OG C|elSM  
int nThreadID; //Thread's ID (ru9Ke%Dx  
boolean bDownOver = false; //Downing is over !8#!P  
boolean bStop = false; //Stop identical 5ZPe=SQ{  
FileAccessI fileAccessI = null; //File Access interface ;44?`[oP  
(_Ld^ ^|  
S[_Hc$7U  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'B$ bGQ  
{ vcsMU|GGh  
this.sURL = sURL; * YhX6J1  
this.nStartPos = nStart; 8r 4 L4  
this.nEndPos = nEnd; qZ8 V/  
nThreadID = id; yzml4/X  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 u{@b_7 5Y  
} ST^@7f_  
G#~6a%VW  
"E><:_,\  
public void run() t\p_QWnF  
{ !{L6 4qI  
while(nStartPos < nEndPos && !bStop) S(5aJ[7Zm  
{ F%v?,`_&I  
OFtAT@ =O  
>;ucwLi  
try{ TN=MZ{L  
URL url = new URL(sURL); sT^^#$ub  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OSvv\3=  
httpConnection.setRequestProperty("User-Agent","NetFox"); lk5}bnd5  
String sProperty = "bytes="+nStartPos+"-"; O 0lQ1<=  
httpConnection.setRequestProperty("RANGE",sProperty); SAa hkX  
Utility.log(sProperty); /wj L<  
_DAAD,'<a  
[P*w$Hn  
InputStream input = httpConnection.getInputStream(); D-zqu~f`  
//logResponseHead(httpConnection); I'_.U]An  
cX64 X  
Ux2p qPb  
byte[] b = new byte[1024]; t-vH\m  
int nRead; & q(D90w.  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~IB~>5U!  
{ zqq$PaH*  
nStartPos += fileAccessI.write(b,0,nRead); xV h-Mx+M  
//if(nThreadID == 1) mST/u>'  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -6+&?f  
} #\&jM -.-  
KL4Z||n  
E+65  
Utility.log("Thread " + nThreadID + " is over!"); JQ*CF(9  
bDownOver = true; D\:~G}M  
//nPos = fileAccessI.write (b,0,nRead); sf|[oD  
} TV>UD q  
catch(Exception e){e.printStackTrace ();} CVi3nS5Yl  
} ;tR,w   
} pGy]t  
}v[$uT-q  
(> v1)*r  
//打印回应的头信息 Tv;|K's'  
public void logResponseHead(HttpURLConnection con) ]0HlPP:2  
{   0%  
for(int i=1;;i++) [-@Lbu-|  
{ FafOd9>AO  
String header=con.getHeaderFieldKey(i); .<|7BHL  
if(header!=null) +^c;4-X 0  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >F zu]G4]  
Utility.log(header+" : "+con.getHeaderField(header)); !J}Bv  
else Xeg g2.Kk  
break; ;UU+:~  
} (i,TxjS'od  
} FS%Xq-c  
0<+=Ew5Z  
crJyk#_  
public void splitterStop() OG_2k3v  
{ CapWn~*g  
bStop = true; W*hRYgaX3  
} c%uX+\-$  
`]^JOw5o  
eeuTf  
} %#rH~E  
3N) bJ  
3B(6^iS  
/* \advFKN  
**FileAccess.java xQ `>\f  
*//文件访问(定位,写) t` R#pQ  
package NetFox; ,H3~mq]  
import java.io.*; xj/ +Z!,9  
nQc]f*  
+h6c Aqm]  
public class FileAccessI implements Serializable{ )g9&fGYf  
R4<}kA,.  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 F6gboo)SD  
RandomAccessFile oSavedFile; Q0f7gY1-%  
long nPos; ZJ} V>Bu-  
i/nA(%_  
AepAlnI@  
public FileAccessI() throws IOException 9S0I<<m  
{ r*K[,  
this("",0); lPh>8:qFM  
} qV$\.T>x  
v1yNVs \}  
IYq)p /  
public FileAccessI(String sName,long nPos) throws IOException 'IweN  
{ (u81p  
oSavedFile = new RandomAccessFile(sName,"rw"); Tp.0@aC  
this.nPos = nPos; r00 fvZyK  
oSavedFile.seek(nPos); S x';Cj-  
} "-Lbz)k  
W9~vBU  
!3{> F"  
public synchronized int write(byte[] b,int nStart,int nLen) C>q,c3s5  
{ V:rq}F}  
int n = -1; **V^8'W<  
try{ ">}l8MA  
oSavedFile.write(b,nStart,nLen); y K~;LV  
n = nLen; a%"My;8  
} dnVl;L8L3  
catch(IOException e) @, D 3$P8}  
{ )W!8,e+%  
e.printStackTrace (); 8[SiIuIV  
} [kx_Izi/T  
2T &<jt  
Lrgv:n  
return n; `1F[.DdF  
} >&mlwxqv  
cB U,!  
, ;L  
} k=2]@K$%  
"8wRx Dr+  
`s (A&=g\  
/* .'C$w1[w  
**SiteInfoBean.java &Avd  
*/ Yxye?R-:  
package NetFox; <o^_il$W  
 $j*j {}K  
r>1M&Y=<  
public class SiteInfoBean { [?mDTD8zU  
Y,OSQBgk  
P g.PD,&U  
private String sSiteURL; //Site's URL 6LRI~*F=3  
private String sFilePath; //Saved File's Path m!3L/UZ  
private String sFileName; //Saved File's Name Ml` f+$  
private int nSplitter; //Count of Splited Downloading File EOu\7;kE9  
6CBk,2DswI  
L;=:OX 0  
public SiteInfoBean() & IVwm"  
{//nSplitter的缺省值为5 $ Scb8<  
//default value of nSplitter is 5 7u]0dHj  
this("","","",5); ]q DhGt  
} aJlSIw*Q,  
Be+CV">2  
$E@L{5Yt  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ">]v'h(s  
{ [Q &{#%M  
sSiteURL= sURL; N"MuAUB:K  
sFilePath = sPath; pqO}=*v@  
sFileName = sName; 2Q`@lTUv  
this.nSplitter = nSpiltter; 6/@"K HHVe  
ZcgSVMqEX  
@e#eAJhU  
} :SilQm*Pl  
8munw  
6k"'3AKaR  
public String getSSiteURL() keNPlK%>  
{ mHjds77e  
return sSiteURL; pIdJ+gu(s  
} |[n-H;0  
O7|0t\)  
Kl<qp7o0  
public void setSSiteURL(String value) :9N~wd  
{ {7 &(2Z]z  
sSiteURL = value; v]|^.x:  
} 9E^IEwq'  
bj4cW\b(  
_y&m4Vuu  
public String getSFilePath() !4cR&@[  
{ E\Hhi.-  
return sFilePath; z5-vx`  
} R,CFU l7Q  
L6yRN>5aE  
ucQ2/B#'4l  
public void setSFilePath(String value) Mw2?U>h1  
{ -M}#-qwf  
sFilePath = value; ;u!qu$O  
} 0Qvbc}KP8  
4*W ??(=j  
PLR[nB7K  
public String getSFileName() E+Z//)1Z  
{ v# ab2  
return sFileName; @K/}Ob4   
} O1IR+"0  
=M^4T?{T  
BuMBnbT  
public void setSFileName(String value) Reca5r1O  
{ zK893)  
sFileName = value; R'f|1mt  
} `9rwu:3i  
$wUFHEl  
(yWU9q)5  
public int getNSplitter() GFasGHAw  
{ u5^fiw]C  
return nSplitter; y&Sl#IQ L  
} mDz{8N9<FG  
mw%do&e  
e`ti*1]q  
public void setNSplitter(int nCount) P3 se"pP  
{ f3Ior.n(  
nSplitter = nCount; P.mz$M  
} -o*IJQ_  
} V.5gxr3QqW  
}I<r=?  
8B;wn<O  
/* @ qWgokf  
**Utility.java 6j{9\ R  
*/ pMM,ox"  
package NetFox; f$$l,wo  
$}&Y$w>S  
]2\|<.  
public class Utility { _]8FCO  
|f1 S&b.  
WGFp<R  
public Utility() {pMbkA Q@  
{ hI*gw3V  
@~% R%Vu  
9,\b$?9  
} |D<J9+  
~*RG|4#  
//线程睡眠 i-[ic!RnKj  
public static void sleep(int nSecond) >2l1t}"\  
{ 5Z/xY &  
try{ 89T xd9X  
Thread.sleep(nSecond); XB*)d 9'8  
} |?{3&'`J8w  
catch(Exception e) IiTV*azVh  
{ >aXyi3B  
e.printStackTrace (); p\OUxAm  
} c}GmS@  
} k4jZu?\C]  
Wr H7tz  
//日志  4b]/2H  
public static void log(String sMsg) \U $'3M  
{ p2 u*{k{  
System.err.println(sMsg); mUY+v>F  
} `s93P^%  
]V*s-och'  
:U_k*9z}=  
public static void log(int sMsg) cM%I5F+n  
{ _$%.F| :  
System.err.println(sMsg); _7r<RZ  
} RGFanP  
} "L^]a$&  
<uZ r.X  
vw VeHjR  
/* @\0U`*]^)  
**TestMethod.java 0 `%eP5  
*/ \M0-$&[+Z  
package NetFox; ?145^ w  
;sd[Q01  
Z.6M~  
public class TestMethod { vAWJP_;J  
Bfe#,  
F N6 GV  
public TestMethod() ,:POo^!/fT  
{ ///xx/weblogic60b2_win.exe ) =-$>75Z  
try{ t}L kl(  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4FURm@C6  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Nn<TPT[,  
SiteFileFetch fileFetch = new SiteFileFetch(bean); wdg,dk9e$  
fileFetch.start(); =K'X:UM  
} AjBwj5K  
catch(Exception e){e.printStackTrace ();} _N!L?b83P  
2"+8NfFl  
" &2Kvsz  
} "D#+:ix8G|  
91%QO?hz  
BSt^QH-'  
public static void main(String[] args) K ZoIjK]  
{ ~I[Z 2&I  
new TestMethod(); "TW%-67  
} y#F`yXUj  
} rTTde^^_  
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
如果您在写长篇帖子又不马上发表,建议存为草稿
认证码:
验证问题:
10+5=?,请输入中文答案:十五