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
  • 8398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
/* 8Zd]wYO  
**SiteFileFetch.java w``U=sfmV  
*/ >^3i|PB  
package NetFox; Qo|\-y-#  
import java.io.*; PCtzl )  
import java.net.*; k!Y, 63V=  
7@W>E;go  
X"eYK/7  
public class SiteFileFetch extends Thread { {+>-7 9b  
JB<t6+"rD  
CU!Dhm/U  
SiteInfoBean siteInfoBean = null; //文件信息Bean |vj/Wwr  
long[] nStartPos; //开始位置 2D5StCF$O  
long[] nEndPos; //结束位置 La[V$+Y  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 [Y`W  
long nFileLength; //文件长度 ]7A'7p $Y  
boolean bFirst = true; //是否第一次取文件 493*{  
boolean bStop = false; //停止标志 7b+6%fV  
File tmpFile; //文件下载的临时信息 ?}Y]|c^W  
DataOutputStream output; //输出到文件的输出流 YN5rml'-  
pd$[8Rmj_  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) a d\ot#V  
public SiteFileFetch(SiteInfoBean bean) throws IOException 4_ML],.  
{ 6_B]MN!(  
siteInfoBean = bean; ,PD QzJY  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); MF'JeM;H  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 8 L Cb+^  
if(tmpFile.exists ()) o)/ 0a  
{ "#g}ve,  
bFirst = false; iWR)ke  
read_nPos(); <F'\lA9  
} J<lW<:!3]  
else JW&gJASGC  
{ uPvEwq* C  
nStartPos = new long[bean.getNSplitter()]; <C*hokqqP  
nEndPos = new long[bean.getNSplitter()]; {{!-Gr  
} ~"A0Rs=  
r9XZ(0/p  
s5. CFA  
*0ro0Z|Iq  
} 6 !bsM"F  
Q,Eo mt  
^<6[.)  
public void run() gRzxLf`K  
{ VIbq:U  
//获得文件长度 * v#o  
//分割文件 %a7$QF]  
//实例FileSplitterFetch @ N m@]q  
//启动FileSplitterFetch线程 ~}Pfu  
//等待子线程返回 B#R|*g:x  
try{ [#iz/q~}  
if(bFirst) NHE18_v5  
{ !VzC&>'v^9  
nFileLength = getFileSize();  ~$J2g  
if(nFileLength == -1) ia? c0xL  
{ [G3E%z  
System.err.println("File Length is not known!"); yt2PU_),  
} RM/ 0A|  
else if(nFileLength == -2) fN2lLn9/u  
{ CvdN"k  
System.err.println("File is not access!"); : rVnc =k  
} cz$2R  
else /mZE/>&~ ,  
{ Zwx%7l;C  
for(int i=0;i<nStartPos.length;i++) 19] E 5'AI  
{ !<h)w#>en  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); xyxy`qRA  
} @(lh%@hO  
for(int i=0;i<nEndPos.length-1;i++) l+b~KU7~l  
{ |vC~HJpuv'  
nEndPos = nStartPos[i+1]; {.]7!ISl5  
} 2KZneS`  
nEndPos[nEndPos.length-1] = nFileLength; ;FEqe 49  
} [fy LV`  
} K)P%;X  
!@"OB~  
rZpXPI  
//启动子线程 3(UVg!t  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %}T6]S)%u  
for(int i=0;i<nStartPos.length;i++) uw8f ~:LT  
{ !`r$"}g  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )M^ gT}M  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]_$[8#kg  
nStartPos,nEndPos,i); p]"4#q\(  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &e3.:[~_?  
fileSplitterFetch.start(); & nK<:^n  
} qJw_  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y_[vr:s5pG  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ")25 qZae  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", S|}L&A  
nEndPos = " + nFileLength);  AOx[  
// fileSplitterFetch[nPos.length-1].start(); i-&yH  
t`QENXA}  
Bbp|!+KP{(  
//等待子线程结束 q cno^8R  
//int count = 0; LH6 vLuf  
//是否结束while循环 }PpUAt~g  
boolean breakWhile = false; _ x*3PE  
>R=|Wo`Ri  
Mb=" Te>|  
while(!bStop) fXB0j;A  
{ Vw"\{`  
write_nPos(); tf G@&&%9  
Utility.sleep(500); fc@A0Hf  
breakWhile = true; 13 wE"-  
048kPXm`  
DV{=n C  
for(int i=0;i<nStartPos.length;i++) M^I(OuRMeI  
{ hv+zGID7  
if(!fileSplitterFetch.bDownOver) PI<vxjOK`  
{ [ /ZO q  
breakWhile = false; :hA#m[  
break; ~)'k 9?0  
} Q@HV- (A  
} Y\tui+?J  
if(breakWhile) !&\INl-Z  
break; tnIX:6  
g=I})s:CTp  
|cY`x(?yP  
//count++; GKCroyor  
//if(count>4) 2"~8Z(0  
// siteStop(); \j.:3X r  
} t g/H2p^Y  
F1hHe<)  
h7@6T+#WoT  
System.err.println("文件下载结束!"); g `4<9RMun  
} mV m Gg,  
catch(Exception e){e.printStackTrace ();} jFb?b6b  
} !o-@&q  
YbLW/E\T  
$ulOp;~A%  
//获得文件长度 L=h'Qgk%  
public long getFileSize() .sA.C] f  
{ 'ig'cRD6N  
int nFileLength = -1; hzC>~Ub5  
try{ PRT +mT  
URL url = new URL(siteInfoBean.getSSiteURL()); SY8C4vb'h  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CH/rp4NeSy  
httpConnection.setRequestProperty("User-Agent","NetFox"); ^W@5TkkBQq  
8$|=P!7EO  
A70d\i  
int responseCode=httpConnection.getResponseCode(); F<w/PMb  
if(responseCode>=400) y!%CffF2  
{  LIdF 0  
processErrorCode(responseCode); s(8W_4&'  
return -2; //-2 represent access is error :i7;w%B  
} ]N[ 5q=A5  
GH xp7H  
*owU)  
String sHeader; |D.ND%K&  
;=UsAB]  
&-=5Xc+Z  
for(int i=1;;i++) {_dvx*M  
{ U%<Inb}ad  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); WN<zkM~3  
//Utility.log(in.readLine()); QdC<Sk!G  
sHeader=httpConnection.getHeaderFieldKey(i); a}u Sm/S  
if(sHeader!=null) . [ mR M  
{ *9i{,I@  
if(sHeader.equals("Content-Length")) |WUG}G")*x  
{ s9d_GhT%-  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); L_s:l9!r  
break; uwBi W  
} v9UD%@tZ  
} #o2[hibq  
else ~v"L!=~G;a  
break; FCn_^l)EA  
} K4);HJ|=  
} w`=\5Oa.G  
catch(IOException e){e.printStackTrace ();} MJrR[h]  
catch(Exception e){e.printStackTrace ();} 'P}0FktP`  
.>nRzgo  
8sCv]|cn  
Utility.log(nFileLength); sT' 5%4  
]0\MmAJRn  
VD\=`r)nT  
return nFileLength; t()c=8qF|u  
} A+)`ZTuO  
v9->nVc-  
F}q c0  
//保存下载信息(文件指针位置) Hq 188<  
private void write_nPos() T,tdL N-  
{ j8`BdKg  
try{ YrKWA  
output = new DataOutputStream(new FileOutputStream(tmpFile)); -PQv ?5  
output.writeInt(nStartPos.length); $tS}LN_!  
for(int i=0;i<nStartPos.length;i++) 9&ids!W~yx  
{ I!?}jo3  
// output.writeLong(nPos); 40<mrVl  
output.writeLong(fileSplitterFetch.nStartPos); _/K_[w 1  
output.writeLong(fileSplitterFetch.nEndPos); PiYxk+N  
} 1sH& sGy7  
output.close(); e 3TI|e_  
} &8 x-o,  
catch(IOException e){e.printStackTrace ();} BVO<e \>3  
catch(Exception e){e.printStackTrace ();} vZoaT|3 G]  
} w1DV\Ap*  
}>X~  
O1mKe%'|  
//读取保存的下载信息(文件指针位置) L,@lp  
private void read_nPos() xZv#Es%#  
{ ?3xzd P  
try{ F@:'J\I}:  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); DDH:)=;z  
int nCount = input.readInt(); VM,]X.  
nStartPos = new long[nCount]; !GGkdg*-*9  
nEndPos = new long[nCount]; 8ITdSg  
for(int i=0;i<nStartPos.length;i++) #YOA`m,'  
{ E\,-XH  
nStartPos = input.readLong(); 1y4  
nEndPos = input.readLong(); ^`>/.gL  
} 0_t`%l=  
input.close(); 8*T=Xei8  
} *`RkTc G  
catch(IOException e){e.printStackTrace ();} `^y7f  
catch(Exception e){e.printStackTrace ();} {> 0wiH#!E  
} ( ICd}  
\;"=QmRD%:  
f`=-US  
private void processErrorCode(int nErrorCode) \} :PLCKT  
{ %1$,Vs<RH  
System.err.println("Error Code : " + nErrorCode); > "=>3  
} HoL Et8Q  
3kMf!VL  
;BIY^6,7e  
//停止文件下载 .h4 \Y A  
public void siteStop() w: Kl6"c  
{ q#=(e:aCb  
bStop = true; 5N&?KA-  
for(int i=0;i<nStartPos.length;i++) J~UuS+Ufv  
fileSplitterFetch.splitterStop(); Tyf`j,=  
Eg3q!J&Z  
C-[eaHJ'$  
} 'ub@]ru|  
} $'hEz/  
//负责部分文件的抓取 :A'y+MnK<  
**FileSplitterFetch.java ';=O 0)u  
*/ '(L7;+E  
package NetFox; [mGLcg6Fw  
M1iS(x  
8eHyL  
import java.io.*; s6^>F/x  
import java.net.*; }d}Ke_Q0  
vTzlwK\#1  
$@"g^,n  
public class FileSplitterFetch extends Thread { ^RtIh-Z.9  
RuVGG)  
<3C*Z"aQ>|  
String sURL; //File URL ^qD$z=z-  
long nStartPos; //File Snippet Start Position cq/$N  
long nEndPos; //File Snippet End Position Y\?"WGL)p  
int nThreadID; //Thread's ID FE|JHh$  
boolean bDownOver = false; //Downing is over @wNG{Stj  
boolean bStop = false; //Stop identical 6MMOf\   
FileAccessI fileAccessI = null; //File Access interface BeoDKdAwY  
JHTSUq  
-0x #  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oEKvl3Hz_  
{ wyO4Y  
this.sURL = sURL; xRLT=.ir  
this.nStartPos = nStart; 'Xq| Kf (  
this.nEndPos = nEnd; 'op|B@y  
nThreadID = id; 8i#2d1O  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~<F8ug #  
} ^N{h3b8  
GH:jH]u!V  
DjQFi  
public void run() T&u5ki4NE  
{ V7fq4O^:  
while(nStartPos < nEndPos && !bStop) 7/@TF/V  
{ \B,@`dw  
.jT#:_  
CxOob1@  
try{ ;LSANr&  
URL url = new URL(sURL); 8_B4?` k  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d K3*;  
httpConnection.setRequestProperty("User-Agent","NetFox"); hVAn>_(  
String sProperty = "bytes="+nStartPos+"-"; Q%tXQP.r  
httpConnection.setRequestProperty("RANGE",sProperty); Eq9x2  
Utility.log(sProperty); 3/e.38m|  
V/ uP%'cd  
vJc-6EO  
InputStream input = httpConnection.getInputStream(); PB`Y g  
//logResponseHead(httpConnection); MSqVlj  
n QZwC  
}1i`6`y1  
byte[] b = new byte[1024]; Tg)| or/ %  
int nRead; [KaAXv .X  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &LZn FR  
{ qqr?!vem6  
nStartPos += fileAccessI.write(b,0,nRead); u^bidd6JRn  
//if(nThreadID == 1) # 0Q]dO  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~{B7 k:  
} bj0G5dc=  
A_ N;   
ZC`wO%,  
Utility.log("Thread " + nThreadID + " is over!"); \[_t]'p  
bDownOver = true; a /l)qB#  
//nPos = fileAccessI.write (b,0,nRead); 0s3%Kqi[  
} >#~& -3  
catch(Exception e){e.printStackTrace ();} _w(7u(Z  
} R0]1xGz  
} (\hx` Yh=>  
i8[t=6Rm@  
0g y/:T  
//打印回应的头信息 %D}kD6=  
public void logResponseHead(HttpURLConnection con) aweV#j(y  
{ {V$|3m>:*  
for(int i=1;;i++) D4-ifsP  
{ JG!mc7  
String header=con.getHeaderFieldKey(i); Cc' 37~6~P  
if(header!=null) 8\ +T8(m  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G"U9E5O  
Utility.log(header+" : "+con.getHeaderField(header)); 7>Ouqxh21  
else K'Tm_"[u  
break; kmsb hYM)  
} I{9QeR I  
} &5spTMw8  
O-~ 7b(Z  
&<5zqsNJ\a  
public void splitterStop() wh\}d4gN  
{ Ng>5?F^v  
bStop = true; YY((V@|K  
} 7BjJhs  
(Hz^)5(~  
ZaDyg"Tw+  
} )oDHeU<&  
z Rl3KjET  
'}JhzKNj  
/* X!Mx5fg  
**FileAccess.java B=yqW  
*//文件访问(定位,写) N^ds RYC  
package NetFox; V>)OpvoT#  
import java.io.*; t?ZI".>  
^ft>@=K(|  
m!4ndO;0vh  
public class FileAccessI implements Serializable{ fc%xS7&  
uK#4(eY=W  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 '(VJ&UlS2  
RandomAccessFile oSavedFile; Y. 5_6'Eo?  
long nPos; gsv uE  
a 3b/e8c  
Lh"<XYY  
public FileAccessI() throws IOException f/NH:1)y  
{ iNz=e=+Si  
this("",0); 3n1;G8Nf  
} }~j lj  
1N^[.=  
z8~NZ;A  
public FileAccessI(String sName,long nPos) throws IOException #`iB`|  
{ +p_CN*10H  
oSavedFile = new RandomAccessFile(sName,"rw"); I^]2K0+x x  
this.nPos = nPos; yw[g!W  
oSavedFile.seek(nPos); NP#w +Qw  
} z^q0/'  
YTpSHpf@  
TJpD{p}  
public synchronized int write(byte[] b,int nStart,int nLen) Ic:(Gi- %  
{ dvx#q5f_S  
int n = -1; }DE g-j,F  
try{ WZejp}x  
oSavedFile.write(b,nStart,nLen); e7r -R3_  
n = nLen; 9ni1f{k  
} C'@i/+  
catch(IOException e) Ae^~Cz1qz  
{ 3!Ij;$  
e.printStackTrace (); tr3! d_  
} ?|C2*?hZ+  
%lx!. G  
ZW8vza  
return n; Y3cMC)  
} };bEU wGWf  
vq0Tk bzs  
ksqQM  
} 9y8&9<#  
Mj?`j_X  
g i-$Z FzB  
/* 4*#18<u5  
**SiteInfoBean.java qI9z;_,gNz  
*/ K5VWt)Z#  
package NetFox; m6K}|j  
_LUhZlw  
K.nHii   
public class SiteInfoBean { ,RI Gc US  
Y>T-af49  
8f 4b&ah  
private String sSiteURL; //Site's URL 4Zddw0|2  
private String sFilePath; //Saved File's Path LTCb@L{^i  
private String sFileName; //Saved File's Name ~&_z2|UXp  
private int nSplitter; //Count of Splited Downloading File T_ <@..C  
d-ZJL6-  
@|m/djN5x  
public SiteInfoBean() oUr66a/[U  
{//nSplitter的缺省值为5 f4b/NG|  
//default value of nSplitter is 5 $q{!5-e  
this("","","",5); _QE qk@ql  
} x7w4[QYw  
")5":V~fN  
Al^d$FaF  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J26 VnK  
{ {n.PF8A5X  
sSiteURL= sURL; :$|HNeDO  
sFilePath = sPath; 7\[@ m3s  
sFileName = sName; M}-Rzc  
this.nSplitter = nSpiltter; |?xN\O^#}  
t%FwXaO#  
G]tn i  
} SrJGTuXg  
^Za-`8#`L  
o#gWbAG;]b  
public String getSSiteURL() |\t-g" ~sN  
{ 7~ p@0)''  
return sSiteURL; b<ZIWfs  
} PO^ij2eS  
'<xXK@=KEI  
"ycJ:Xv49  
public void setSSiteURL(String value) 2r4Uh1D~  
{ 6=/F$|  
sSiteURL = value; mb3"U"ohs  
}  -p-ZzgQ  
cn3\kT*  
'n]w"]|  
public String getSFilePath() jo@6?( *4  
{ F6|]4H.3Q  
return sFilePath; 1D7 `YKI9h  
} [Ek7b *  
M `M5'f  
ZzpUUH/r  
public void setSFilePath(String value) :#ik. D  
{ ^|>PA:%  
sFilePath = value; n\D&!y[]F  
} 5`  ~JPt  
IdYt\^@>  
RJ&RTo  
public String getSFileName() xn(kKB.  
{ ?4&e;83_#y  
return sFileName; vWv"  
} rfJz8uF%  
$6 9&O  
,Vm < rK  
public void setSFileName(String value) hH 3RP{'=  
{ {9pZ)tB  
sFileName = value; c_pr  
} UHkMn  
! E5HN :#  
Lv7(st%`  
public int getNSplitter() 3M7/?TMw{6  
{ Tv=mgH=b  
return nSplitter; uyWunpT  
} 2- h{N  
qgHWUwr+n  
AKfDXy  
public void setNSplitter(int nCount) ((;!<5-`s  
{ Eyqa?$R  
nSplitter = nCount; C2I_%nU Z1  
} b\!_cb~"@  
} $( kF#  
]:-mbgW  
0i>5<ej,f  
/* k%#EEMh  
**Utility.java "Gzz4D  
*/ lgy <?LI\  
package NetFox; @Uvz8*b6  
tSUEZ62EY  
'GWN~5  
public class Utility { b. '-?Nn  
P3=G1=47U  
MJO-q $)c  
public Utility() ksUcx4;a@F  
{ -d/ =5yxL  
d&Zpkbh"  
yx[/|nZDC4  
}  7xlkZF  
Mb}QD~=M  
//线程睡眠 8kIksy  
public static void sleep(int nSecond) 1R%.p7@5QU  
{ Pmx -8w  
try{ )2o?#8J  
Thread.sleep(nSecond); O 8r|8]o  
} pah'>dAL  
catch(Exception e) t!l&iVWs  
{ ^[`%&uj!g  
e.printStackTrace (); SKN`2hD  
} u c)eil  
} [|$h*YK  
{}przrU^c  
//日志 &Z@o Q  
public static void log(String sMsg) RbnVL$c  
{ N>`Aw^ _@&  
System.err.println(sMsg); +Kc  
} vh%B[brUJ  
nR~@#P\  
T?0eVvM  
public static void log(int sMsg) BDDlQci38  
{ O0v}43J [  
System.err.println(sMsg); F/{!tx  
} T'9'G M  
} Sz`,X0a  
RtS+<^2a;  
? OM!+O  
/* 1CZgb   
**TestMethod.java T7%S #0,p  
*/ 6d}lw6L  
package NetFox; F)QDJE0  
]_gU#,8  
q3!bky\  
public class TestMethod { @S;'@VC  
/,yd+wcW#  
!e<^? r4  
public TestMethod()  kDioD  
{ ///xx/weblogic60b2_win.exe bAqA1y3=  
try{ .L~AL|2_  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (w3YvG.  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2/^3WY1U  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ES7s1O$#  
fileFetch.start(); ouQ T  
} M6j y\<a  
catch(Exception e){e.printStackTrace ();} ~36!?&eA8  
g3y~bf  
@": ^)87  
} tyFzSrfc  
8GUX{K  
n-;`Cy`k  
public static void main(String[] args) k y7Gwc  
{ wi=v}R_  
new TestMethod(); vk^xT  
} n7[V&`e_  
} 1Pu~X \sO  
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
欢迎提供真实交流,考虑发帖者的感受
认证码:
验证问题:
10+5=?,请输入中文答案:十五