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
  • 9856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
/* A]1dR\p  
**SiteFileFetch.java Dbb=d8utE  
*/ e}n(mq  
package NetFox; mmG]|Cl@  
import java.io.*; F8#MI G   
import java.net.*; Vvp{y  
^Nu j/  
KEdqA/F>  
public class SiteFileFetch extends Thread { 'V8o["P  
0+[3>Ny 0  
`l6OQdB3W  
SiteInfoBean siteInfoBean = null; //文件信息Bean 1Y%lt5,*  
long[] nStartPos; //开始位置 -0TI7 @  
long[] nEndPos; //结束位置 HXX9D&c4R  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 a^\ F9^j  
long nFileLength; //文件长度 Gm &jlN  
boolean bFirst = true; //是否第一次取文件 O.Y|},F  
boolean bStop = false; //停止标志 r;{ggwY&J  
File tmpFile; //文件下载的临时信息 H0jbG;  
DataOutputStream output; //输出到文件的输出流 8C[eHC*r  
WYP\J1sy  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) JpZ_cb`<E'  
public SiteFileFetch(SiteInfoBean bean) throws IOException }{kn/m/  
{ :S}ZF$ $j%  
siteInfoBean = bean; /0!.u[t)~  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); zqURnsJ  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ';}:*nZ//_  
if(tmpFile.exists ()) 'n^?DPvD  
{ j&U7xv  
bFirst = false; !Pt4\  
read_nPos(); @4KKm@(p85  
} w `+.F;}s  
else kd_! S[  
{ 66sgs16k  
nStartPos = new long[bean.getNSplitter()]; lHPnAaue@  
nEndPos = new long[bean.getNSplitter()]; }@/Ox  
} =M9R~J!  
Qmb+%z  
;JgSA&'e  
1]Cb i7  
}  deq5u>  
[mNum3e  
wkx#WC  
public void run() $at\aJ  
{ CIsX$W  
//获得文件长度 }D`ZWTjDay  
//分割文件 ,9"du  
//实例FileSplitterFetch 4=`1C-v?q  
//启动FileSplitterFetch线程 X$G:3uoN  
//等待子线程返回 V|F/ynJfA  
try{ \){_\{&  
if(bFirst) q(WGvl^r  
{  Lsai8 B  
nFileLength = getFileSize(); .gN ziDO  
if(nFileLength == -1) xi4b;U j  
{ G$)tp^%]  
System.err.println("File Length is not known!"); [O}D^qp  
} .:4*HB  
else if(nFileLength == -2) I+ 3qu=  
{ BHS@whj  
System.err.println("File is not access!"); *_m ER`  
} Q[%G`;e#  
else J_j4Zb% K  
{ >e(@!\ x  
for(int i=0;i<nStartPos.length;i++) 7]Hf3]e>/  
{ /?0|hi<_$  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); #%8)'=1+4?  
} L]Xx-S  
for(int i=0;i<nEndPos.length-1;i++) pAq PHD=  
{ O*lIZ,!n  
nEndPos = nStartPos[i+1]; 7xY&7 x(v  
} nr8#;D  
nEndPos[nEndPos.length-1] = nFileLength; ,aq>9\ pi  
} +fKV/tSWi  
} ;8 *"c  
%rf6 >  
__1Hx?f  
//启动子线程 XMykUr e|  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {X<_Y<  
for(int i=0;i<nStartPos.length;i++) MtgY `p  
{ 44t;#6p@%>  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \VI0/G)L  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), lp5'-Jo  
nStartPos,nEndPos,i); k^cnNx  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '/rU<.1  
fileSplitterFetch.start(); =3rf}bl2  
} :oYSvK7>  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *-.`Q  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]/3!t=La  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s jaaZx1  
nEndPos = " + nFileLength); p2fzbBt  
// fileSplitterFetch[nPos.length-1].start(); t$p%UyVE  
LaZ @4/z!  
8Fbt >-N<\  
//等待子线程结束 Im};wJ&  
//int count = 0; (lq%4h  
//是否结束while循环 bE=[P}E  
boolean breakWhile = false; DY/%|w*L  
hOV5WO\  
7:=(yBG  
while(!bStop) EM1HwapD  
{ V?>&9D"m  
write_nPos(); k8SY=HP  
Utility.sleep(500); F x$W3FIO]  
breakWhile = true; %s5( ''a.  
33a}M;vx  
a@9W'/?igk  
for(int i=0;i<nStartPos.length;i++) ep`8LQf  
{ M\Wg|gpy  
if(!fileSplitterFetch.bDownOver) rTOex]@N  
{ (9'q/qgTO  
breakWhile = false; ZEpu5`  
break; 9"/=D9o9  
} ;NAKU  
} ;<6S\  
if(breakWhile) Q84XmXm|  
break; t-iQaobF  
}dqOE-"I"n  
.vIRz-S  
//count++; }N,v&  B  
//if(count>4) C.H(aX)7  
// siteStop(); *+2BZ ZwT  
} W'E3_dj+  
VG$%Vs  
Tc/<b2 \g  
System.err.println("文件下载结束!"); ycEp,V;[Z  
} hh.`Yu L  
catch(Exception e){e.printStackTrace ();} LW/> %  
} ]n'.}"8Kn  
nDLiER;U  
%x}Unk  
//获得文件长度 }XRfHQk  
public long getFileSize() YluvWHWi  
{ OU^I/TU  
int nFileLength = -1; &sXk!!85:  
try{ #"H<k(-Cz  
URL url = new URL(siteInfoBean.getSSiteURL()); %RzkP}1>E  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Lm0q/d2|\X  
httpConnection.setRequestProperty("User-Agent","NetFox"); us<dw@P7{  
Y9%zo~]-W'  
|="Y3}a  
int responseCode=httpConnection.getResponseCode(); (9] =;)  
if(responseCode>=400) 5twG2p8  
{ b `cH.v  
processErrorCode(responseCode); f,3K;S-he:  
return -2; //-2 represent access is error 83'rQDo)G  
} a", 8N"'  
Q(Pc  
k>E/)9%ep2  
String sHeader; 8)b*q\ O'  
n2["Ln mO  
Np.<&`p!  
for(int i=1;;i++) =^zOM6E1ZF  
{ ZKB27D_vg>  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h<WTN_i}  
//Utility.log(in.readLine()); +<f+kh2L  
sHeader=httpConnection.getHeaderFieldKey(i); Qi9M4Yv  
if(sHeader!=null) jq|fI P  
{ 6}\J-A/  
if(sHeader.equals("Content-Length")) 'X_%m~}N  
{ \@^` G  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^~bAixH^k  
break; \#"&S@%c  
} q _:7uQ  
} /q"8sj/  
else )G#O#Yy  
break; 3Ea/)EB]  
} y99|V39'  
} Xcg+ SOB  
catch(IOException e){e.printStackTrace ();} xp\6,Jyh  
catch(Exception e){e.printStackTrace ();} h<!!r  
sX`by\s,  
|~Vq"6`  
Utility.log(nFileLength); G49`a*Jn  
!4$o*{9Lx:  
e\*N Lj_(  
return nFileLength; S3c%</'  
} /AUX7 m.8  
~(^?M  
VlxHZ  
//保存下载信息(文件指针位置) edlsS}8^  
private void write_nPos() \YsLVOv%:d  
{ v.Q+4 k  
try{ U/\LOIs  
output = new DataOutputStream(new FileOutputStream(tmpFile)); N'%l/  
output.writeInt(nStartPos.length); r+h$]OJ  
for(int i=0;i<nStartPos.length;i++) irGgo-x  
{ 1%N[DA^<\  
// output.writeLong(nPos); jF{\=&fU  
output.writeLong(fileSplitterFetch.nStartPos); QG XR<Y  
output.writeLong(fileSplitterFetch.nEndPos); njb{   
} "?"+1S  
output.close(); O[9A}g2~  
} ,sp((SF]1  
catch(IOException e){e.printStackTrace ();} qa?0GTAS  
catch(Exception e){e.printStackTrace ();} V%FWZn^  
} ]sB%j@G  
d{]2Q9g  
?T'a{ ~]R  
//读取保存的下载信息(文件指针位置) ;7mE%1X  
private void read_nPos() >WY\P4)k  
{ (<Kf  
try{ q]P$NeEiZ"  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); uCf _O~  
int nCount = input.readInt(); *p^*>~i9)  
nStartPos = new long[nCount]; ygqWy1C  
nEndPos = new long[nCount]; Mqmy*m[U  
for(int i=0;i<nStartPos.length;i++) V_=7q=9mV  
{ p8E6_%Rw  
nStartPos = input.readLong(); '77Gg  
nEndPos = input.readLong(); T K Ec ^  
} l3YS_WBSn  
input.close(); [4\n(/  
} GbBz;ZV%z,  
catch(IOException e){e.printStackTrace ();} c7 O$< F  
catch(Exception e){e.printStackTrace ();} 5 r&n  
} a,?u 2  
JZoH -  
$HFimU,V=0  
private void processErrorCode(int nErrorCode) 0JV|wd8j  
{ ,4S6F HK  
System.err.println("Error Code : " + nErrorCode); OZ Hfd7K4A  
} +^ |=MK%  
;PWx#v+vwF  
1&utf0TX6q  
//停止文件下载 .J2tm2]"EZ  
public void siteStop() lXu6=r  
{ :v8~'cZ  
bStop = true; $`|\aXd[C*  
for(int i=0;i<nStartPos.length;i++) >8w=Vlp  
fileSplitterFetch.splitterStop(); e]3b0`E  
c+G%o8  
sN@=Ri?\  
} ko`KAU<T_  
} SfGl*2  
//负责部分文件的抓取 ?w>-ya  
**FileSplitterFetch.java /jd.<r=_I  
*/ 4cJka~  
package NetFox; 'a=QCO 0  
(L !#2Jy  
 *#sY-Gd  
import java.io.*; )'axJ  
import java.net.*; ~x g#6%<=  
f9?f!k  
=(p]L  
public class FileSplitterFetch extends Thread { dC 8,  
,<]~/5-f  
>~rytg]f  
String sURL; //File URL A=\:b^\  
long nStartPos; //File Snippet Start Position C dTE~O<)  
long nEndPos; //File Snippet End Position &u9@FFBT8  
int nThreadID; //Thread's ID n~?n+\.&a  
boolean bDownOver = false; //Downing is over Aiqn6BX{  
boolean bStop = false; //Stop identical G!5~`v  
FileAccessI fileAccessI = null; //File Access interface Tu}?Q. pKo  
&K-0ld(;  
G[a&r  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \@GKVssw  
{ W=!di3IA  
this.sURL = sURL; FYX" q-Z  
this.nStartPos = nStart; c"`CvQO64  
this.nEndPos = nEnd; _|s'0F/t  
nThreadID = id; {M P (*N  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )~ghb"K  
} a>BPK"K2  
t}f,j^`e  
~cb7]^#u1l  
public void run() "\l#q$1h  
{ asKAHVT(  
while(nStartPos < nEndPos && !bStop) nlR7V.  
{ NrWgaPO)i  
=4:]V\o):'  
)o_Pnq9_  
try{ 1'BC R  
URL url = new URL(sURL); `z?h=&N  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ) 0|X];sD  
httpConnection.setRequestProperty("User-Agent","NetFox"); .dTXC'  
String sProperty = "bytes="+nStartPos+"-"; H{VJ S Jc{  
httpConnection.setRequestProperty("RANGE",sProperty); )]3_o!o  
Utility.log(sProperty); ,p9>/)l  
R}HNi(%"  
dNT<![X\  
InputStream input = httpConnection.getInputStream(); W&;,7T8@  
//logResponseHead(httpConnection); H.*aVb$  
+VRM:&  
9]PMti  
byte[] b = new byte[1024]; T<K/bzB3z  
int nRead; t-VU&.Y  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) XSe\@t~&g  
{ D;+sStZK3  
nStartPos += fileAccessI.write(b,0,nRead); +$ 0wBU  
//if(nThreadID == 1) 4LkW`Sbm  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zL/r V<  
} (Kb_/  
ECr}7R%  
xpB* > zb  
Utility.log("Thread " + nThreadID + " is over!"); Wr;9Mz&{  
bDownOver = true; -5d^n\CDK  
//nPos = fileAccessI.write (b,0,nRead); J @^Ypq  
} #B!<gA$/  
catch(Exception e){e.printStackTrace ();} 9 1ndr@*|  
} c^x5 E`{  
} @"O|[%7e  
gfly?)VnF  
c, FZ{O@  
//打印回应的头信息 0artR~*}  
public void logResponseHead(HttpURLConnection con) g& ?{^4t]  
{ l$g \t]  
for(int i=1;;i++) =a!_H=+4  
{ \<W/Z.}/  
String header=con.getHeaderFieldKey(i); F6gU9=F1<  
if(header!=null) 'QC'*Hl  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /xw}]Fa5  
Utility.log(header+" : "+con.getHeaderField(header)); G:i>MJbxT  
else nr- 32u  
break; AY_GD ^  
} D&!c7_^  
} hK 1 H'~c  
K2!GpGZu  
qw6i|JM%  
public void splitterStop() _DLELcH Y  
{ 0rCQz3gh1  
bStop = true; uG=~k O  
} ~+CEek  
fRomP-S  
bO+]1nZ.  
} <KBS ;t="1  
a9g~(#?a  
(qDPGd*1  
/* k]9+/ $  
**FileAccess.java tx,q=.(  
*//文件访问(定位,写) @!p0<&R@x  
package NetFox; @|EWif|  
import java.io.*; sr-tZ^d5S?  
e&-MP;kgW9  
aI_[h v  
public class FileAccessI implements Serializable{ <7_s'UAL!  
?ZP@H _w6}  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 tui5?\  
RandomAccessFile oSavedFile; Hd57Iw  
long nPos; L'u*WHj|v  
'9@AhiNV  
#T++5G  
public FileAccessI() throws IOException K8RV=3MBLD  
{ l- $5CO  
this("",0); U<I]_]  
} t 09-y  
aW_Pv~  
N^4CA@'{  
public FileAccessI(String sName,long nPos) throws IOException xiOAj"}~  
{ c'SjH".[  
oSavedFile = new RandomAccessFile(sName,"rw"); ;$'D13  
this.nPos = nPos; `wKd##v'@  
oSavedFile.seek(nPos); Af Y ]i  
} U3~rtc*  
y 'Ah*h  
A$70!5*  
public synchronized int write(byte[] b,int nStart,int nLen) bMB*9<c~  
{ <RuLIu  
int n = -1; $g_|U:,  
try{ .S*VYt%K7  
oSavedFile.write(b,nStart,nLen); <FfmDR  
n = nLen; 0( q:K6zI}  
} )3.=)?XW  
catch(IOException e) TgA>(HcO  
{ _o? I=UN2:  
e.printStackTrace (); `t3w|%La}  
} LjCUkbzQF  
rqz48~\lJ  
zE+^WeH|  
return n; =rA]kGx  
} [@Mo3]#\  
m>djoe  
rlY n"3%  
} jEn 9T  
$bl<mG%#9  
?-JW2 E"uT  
/* '0v]?mM  
**SiteInfoBean.java iLQ;`/j  
*/ l~mj>$  
package NetFox; Zi{vEI]  
U#:N/ts*(  
X 4\V4_  
public class SiteInfoBean { <l5s[  
Cd|rDa  
80K"u[  
private String sSiteURL; //Site's URL eW;c 3<  
private String sFilePath; //Saved File's Path r4Xaa<  
private String sFileName; //Saved File's Name S 9|^VU  
private int nSplitter; //Count of Splited Downloading File 8>`8p0I$+  
Oj '^Ww m  
$B`ETI9g-N  
public SiteInfoBean() Vg}+w Nt5  
{//nSplitter的缺省值为5 cN`P5xP'  
//default value of nSplitter is 5 VFq7nV/O  
this("","","",5); IV~5Y{(l  
} m -0}Pe9L  
a:KL{e[   
G "ixw  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) hqa6aYY x  
{ 3gYtu-1  
sSiteURL= sURL; 1n[wk'}qf4  
sFilePath = sPath; 8X/SNRk6p  
sFileName = sName; vAjog])9s  
this.nSplitter = nSpiltter; !-t"}^)  
f|Nkk*9$  
>M^:x-mib  
} >sQf{uL  
q#K0EAgC  
mR$0Ij/v  
public String getSSiteURL() :s1.TQ;Y(  
{ eQ,VK`7X  
return sSiteURL; Y.kc,~vYL  
} /#j)GlNp:  
`5n^DP*X  
SeuDJxqopD  
public void setSSiteURL(String value) !&5|:96o  
{ 89t"2|9 u  
sSiteURL = value; /Mj|Px%  
} 2fXwJG'  
8! /ue.T  
(yoF  
public String getSFilePath() ZCA= n  
{ @2`nBtk  
return sFilePath; ng9 _c  
} Wu/:ES)C  
`|mV~F|  
c *i,z  
public void setSFilePath(String value) \eAV: qV  
{ J!">L+Zcx  
sFilePath = value; &'Xgf!x  
} 9*XT|B  
ilZQ/hOBH  
{asq[;]  
public String getSFileName() ` l %,4qR  
{ {REGoe=W%  
return sFileName; >h.HW  
} rr>6;  
GC_c.|'6[  
)~`UDaj_  
public void setSFileName(String value) _Ud!tK*H  
{ +pQ3bX  
sFileName = value; A)&CI6(  
} w|NId,#f  
M!X^2  
(EH}lh }%  
public int getNSplitter() i~)EU F  
{ ,W;|K 5  
return nSplitter; "U$](k.<VA  
} }}bMq.Q'  
[.6bxK  
8"p rWAN  
public void setNSplitter(int nCount) vP\6=71Y  
{ Ggy?5N7P  
nSplitter = nCount; #w8.aNU+]  
} h iK}&  
} F{_,IQ]U  
0g; o6Fg  
I!Mkss xc  
/* ^ > ?C  
**Utility.java ^/#8 "  
*/ h"'}Z^  
package NetFox; Fc=6 *.hy  
L\!Oj5  
 4,?beA  
public class Utility { /c6]DQ<?  
`wr*@/P  
J|@D @\?7  
public Utility() 3o"l sly  
{ +}Mm5^6*  
?.n1t@sG&  
7xR:\FBa^  
} ` k(Q:  
nc1?c1s,f  
//线程睡眠 vZs~=nfi#|  
public static void sleep(int nSecond) jVHS1Vsei  
{ _>r (T4}]  
try{ jhBfy|Ftu  
Thread.sleep(nSecond); P*OT&q  
} (cV1Pmn  
catch(Exception e) ]z| 2  
{ C5jt(!pi  
e.printStackTrace (); a^ys7UV  
} .F[5{XV  
} t:v>W8N53  
P0U&+^W"9  
//日志 4ElS_u^cP7  
public static void log(String sMsg) C~'.3Q6  
{ [fELf(;(  
System.err.println(sMsg); V|*3*W  
} [57`V &c5  
8@|{n`n]  
\< a^5'  
public static void log(int sMsg) xsNOjHk  
{ mS49l  
System.err.println(sMsg); zAev@+.ld  
} 91DevizXx  
} z46Sh&+  
=h+-1zp{M^  
=kzHZc  
/* U-U(_W5&  
**TestMethod.java kf#S"[/E  
*/ NzN"_ojM  
package NetFox; Zv?"1Y< L  
NL2D,  
Q]/{6:C  
public class TestMethod { %:Y(x$Qy  
%*Vr}@BA)  
5KIhk`S  
public TestMethod() lhf5[Rp  
{ ///xx/weblogic60b2_win.exe l)'*jZ  
try{ sE!g!ht  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); u yE#EnsH  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,f<J4U:Y  
SiteFileFetch fileFetch = new SiteFileFetch(bean); jM-5aj[K  
fileFetch.start(); H ]!P[?  
} Vs Z7 n~e  
catch(Exception e){e.printStackTrace ();} qv4r !x  
6\ .LG4@LO  
_::ssnG3jT  
} ikb77 ?.  
\((5Sd  
@=Dc(5`[  
public static void main(String[] args) ?ef7%0  
{ yf-2E_yB  
new TestMethod(); (T&(PCw|  
} Ug4o2n0sk  
} 1Tev&J  
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
如果您提交过一次失败了,可以用”恢复数据”来恢复帖子内容
认证码:
验证问题:
10+5=?,请输入中文答案:十五