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
  • 8389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
/* s4`,Z*H  
**SiteFileFetch.java *cP(3n3]R  
*/ Aa+<4 R  
package NetFox; kx,3[qe'S  
import java.io.*; %v4*$E!f  
import java.net.*; VDFs.;:s  
1*f*}M  
d7G DIYH<  
public class SiteFileFetch extends Thread { *]:J@KGf  
;(@' +"  
az[#q  
SiteInfoBean siteInfoBean = null; //文件信息Bean oU|_(p"e|  
long[] nStartPos; //开始位置 7.kgQ"?&  
long[] nEndPos; //结束位置 HX{K5+  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 k=4C"   
long nFileLength; //文件长度 l5nm.i<M  
boolean bFirst = true; //是否第一次取文件 vA2>&YDFX  
boolean bStop = false; //停止标志 qVW3oj<2  
File tmpFile; //文件下载的临时信息 WK5B8u*<  
DataOutputStream output; //输出到文件的输出流 lhX4 MB"  
>dJ[1s]  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 4_-L1WH  
public SiteFileFetch(SiteInfoBean bean) throws IOException LP'~7FG  
{ Q`!^EyRA:^  
siteInfoBean = bean; ~t1?oJ  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); DQ@M?~1hp  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); EXsVZg"#  
if(tmpFile.exists ()) 'cqY-64CJZ  
{ SLz;5%CPV  
bFirst = false; o@L2c3?c5  
read_nPos(); sI6I5  
} 7+;.Q  
else ~^PNMZk  
{ .%+anVXS  
nStartPos = new long[bean.getNSplitter()]; Dy*K;e-+  
nEndPos = new long[bean.getNSplitter()]; E|A~T7G=  
} 8 ,W*)Q  
Bbtc[@"X  
L d{`k  
|AXV4{j_i  
} {:#c1d2@8  
N;a'`l  
WfHa  
public void run() Lvrflx*Q  
{ A ^t _"J  
//获得文件长度 mU]pK5  
//分割文件 RivhEc1h%  
//实例FileSplitterFetch ?{P$|:ha  
//启动FileSplitterFetch线程 >sZ_I?YDs  
//等待子线程返回 FX!Qd&kl1  
try{ 1vYa&!  
if(bFirst) N cp   
{ }USOWsLSt  
nFileLength = getFileSize(); m%nRHT0KAf  
if(nFileLength == -1) D`fIw` _  
{ D!8v$(#hR  
System.err.println("File Length is not known!"); TK0WfWch  
} >)HKruSW.  
else if(nFileLength == -2) 'nS>'yYH#  
{ shEAr*u  
System.err.println("File is not access!"); N85ZbmU~  
} FNs$k=* 8  
else  U02  
{ FOhq&\nkU  
for(int i=0;i<nStartPos.length;i++) qDcoccEf  
{ 3 }3C*w+  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 8|nc( $}~  
} +R7pdi  
for(int i=0;i<nEndPos.length-1;i++) BSL+Gjj~}  
{ Fkg%_v$  
nEndPos = nStartPos[i+1]; B.!&z-)#  
} c D .;  
nEndPos[nEndPos.length-1] = nFileLength; jZH4]^De  
} uqD|j:~ =k  
} 1SH]$V4C  
Yr\quinLL  
,4=mlte"  
//启动子线程 $wyPGok  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; QX42^]({;c  
for(int i=0;i<nStartPos.length;i++) 2.^CIJc  
{ "YAnGGx)LZ  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >*uj )u%  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), q8uq%wf  
nStartPos,nEndPos,i); O`I}Lg]~q  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~~O4!|t  
fileSplitterFetch.start(); ,fhF-%Q!g  
} `(DHa=s1  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "$P/ek  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); I%($,kd}s  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U5OFw+J  
nEndPos = " + nFileLength); pWn]$HaoG  
// fileSplitterFetch[nPos.length-1].start(); M& )yr^  
Vvp{y  
I2-ue 63 ?  
//等待子线程结束 KEdqA/F>  
//int count = 0; \6bvk _  
//是否结束while循环 +_25E.>ml  
boolean breakWhile = false; ~Ye nH  
=nO:R,U  
]+b?J0|P<  
while(!bStop) WJI}~/z;C  
{ .Yvy37n((  
write_nPos(); lANi$ :aE  
Utility.sleep(500); ,tDLpnB@;  
breakWhile = true; J@QOF+&  
DliDBArxZ  
aHb&+/HZ  
for(int i=0;i<nStartPos.length;i++) #s ' `bF^  
{ F+?i{$  
if(!fileSplitterFetch.bDownOver) XfflD9M  
{ &g>M Z" Z|  
breakWhile = false; cP4C<UG  
break; m 2/S(f  
} Udf\;G@  
} B.KK@  
if(breakWhile) CEBu[TT/9  
break; O9m sPb:  
zo("v*d*q  
#DARZhU)  
//count++; m%UF{I,  
//if(count>4) '+ mI  
// siteStop(); atW^^4 :  
} t~)4f.F:  
df {\O* 6  
Ujqnl>l  
System.err.println("文件下载结束!");  @' %XdH  
} i[MBO`FF  
catch(Exception e){e.printStackTrace ();} K9Onjs% U  
} SL/'UoYm<  
.Wr7*J[V.  
v;-0^s/P  
//获得文件长度 > 5?c93?  
public long getFileSize() kw} E0uY  
{ j+S&5C/{  
int nFileLength = -1; -ik=P ]?  
try{ j}K 3YfH  
URL url = new URL(siteInfoBean.getSSiteURL()); Z op/ MeI  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4^k8| # c  
httpConnection.setRequestProperty("User-Agent","NetFox"); [z"oi'"fQ  
)2 q r^)  
!I\eIV>0b  
int responseCode=httpConnection.getResponseCode(); P : L6Zo-J  
if(responseCode>=400) K>5 bb  
{ LN5BU,4=  
processErrorCode(responseCode); F_i"v5#  
return -2; //-2 represent access is error #f;6Ia>#  
} _|4QrZ$n(  
.r&CIL >  
1f 1D^|  
String sHeader; IwS<p -  
|'uBkL0q  
ueg%D +u  
for(int i=1;;i++) Q[%G`;e#  
{ J_j4Zb% K  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >e(@!\ x  
//Utility.log(in.readLine()); MxUQF?@6  
sHeader=httpConnection.getHeaderFieldKey(i); /?0|hi<_$  
if(sHeader!=null) Wb#<ctM>  
{ L>&{<M_  
if(sHeader.equals("Content-Length")) W voIh4]  
{ 9$qw&j[  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); -e?n4YO*\  
break; VKw.g@BY  
} XR p60i6f  
} lqgR4  !  
else osmCwM4O  
break; Jt0/*^'  
} 5\O&pz@D  
} XbeT x  
catch(IOException e){e.printStackTrace ();} 2P${5WT  
catch(Exception e){e.printStackTrace ();} :cIPX%S  
*b!.9pK  
k_Sm ep  
Utility.log(nFileLength); K6)IBV;  
!>wu7u-  
f_;tFP B  
return nFileLength; t$p%UyVE  
} PI9aKNt  
Uq x@9z(  
bE=[P}E  
//保存下载信息(文件指针位置) V\Y, 4&bI  
private void write_nPos() JlawkA  
{ h/y0Q~|/d  
try{ #N'9F&:V$  
output = new DataOutputStream(new FileOutputStream(tmpFile)); u[4h|*'"|  
output.writeInt(nStartPos.length); @at*E%T[  
for(int i=0;i<nStartPos.length;i++) |5q,%9_  
{ iCGHcN^3  
// output.writeLong(nPos); .b!HEi<F  
output.writeLong(fileSplitterFetch.nStartPos); V`i(vC(  
output.writeLong(fileSplitterFetch.nEndPos); E0aFHC[  
} BLt_(S?Z`  
output.close(); Se\iM s  
} e5lJ)_o  
catch(IOException e){e.printStackTrace ();} aW;)-0+  
catch(Exception e){e.printStackTrace ();} 1Mx2%  
} U+(qfa5(  
C.H(aX)7  
V' i@N  
//读取保存的下载信息(文件指针位置) uKJo5%>  
private void read_nPos() lQt,(@7]  
{ B{S^t\T$  
try{ mZ3Z8q}%P  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Wh"xt:  
int nCount = input.readInt(); :; La V  
nStartPos = new long[nCount]; Y[m*  
nEndPos = new long[nCount]; D$D;'Kij  
for(int i=0;i<nStartPos.length;i++) D.a\O9q"&{  
{ s%m?Yh3  
nStartPos = input.readLong(); c"Q9ob  
nEndPos = input.readLong(); o?3C-A|  
} BHNJH  
input.close(); qA25P<  
} U9%^gC  
catch(IOException e){e.printStackTrace ();} 'g} Q@@b  
catch(Exception e){e.printStackTrace ();} >{rD3X"d  
} ?8<R)hJa<  
<BBSC  
fq):'E)  
private void processErrorCode(int nErrorCode) M{Vi4ehOq  
{ jq|fI P  
System.err.println("Error Code : " + nErrorCode); ]*{tno  
} jT-tsQ .,  
Go~3L8 '  
:/fT8KCwo  
//停止文件下载 : D !/.0  
public void siteStop() F7=&CW 0  
{ k4"O} jQO  
bStop = true; _gCi@uXS3  
for(int i=0;i<nStartPos.length;i++) Rp}Sm,w(  
fileSplitterFetch.splitterStop(); Q[aBxy (  
H^$7=  
5<oV>|*@{  
} Ik=bgEF  
} ag!q:6&  
//负责部分文件的抓取 A{DE7gp!  
**FileSplitterFetch.java Z[\nyj  
*/ ),-MrL8c%  
package NetFox; _M- PF$  
WOYN% 0#  
i[vOpg]J  
import java.io.*; H1vToIP%  
import java.net.*; th{Ib@o  
r#6djs1  
#!4 HSBf  
public class FileSplitterFetch extends Thread { I5rAL\y-G  
-8t&&fIA  
n3s  
String sURL; //File URL U {9yfy  
long nStartPos; //File Snippet Start Position IBh?vh  
long nEndPos; //File Snippet End Position )hfI,9I~  
int nThreadID; //Thread's ID uC 2{ Mmy  
boolean bDownOver = false; //Downing is over 0qN+W&H  
boolean bStop = false; //Stop identical o& ?:pE  
FileAccessI fileAccessI = null; //File Access interface l<s6Uu"  
A_5M\iN\  
]Lm?3$u$  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^F|/\i   
{ difAQ<`  
this.sURL = sURL; {9nH#yv  
this.nStartPos = nStart; v%E!  
this.nEndPos = nEnd; 4Jw_gOY&D  
nThreadID = id; @ | (Tg  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 MQo/R,F }  
} (<Kf  
q]P$NeEiZ"  
}>'1Qg  
public void run() E*}1_,q)  
{ l9{.~]V  
while(nStartPos < nEndPos && !bStop) |vh{Kb@  
{ ;n/04z  
Ve[&_(fP  
6>Is-/hsy  
try{ } FC(Z-g  
URL url = new URL(sURL); M#SGZ~=1r  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :g)`V4%  
httpConnection.setRequestProperty("User-Agent","NetFox"); _%PEv{H0.  
String sProperty = "bytes="+nStartPos+"-"; 7qhX `$  
httpConnection.setRequestProperty("RANGE",sProperty); l3YS_WBSn  
Utility.log(sProperty); [4\n(/  
zj#8@gbh+  
c7 O$< F  
InputStream input = httpConnection.getInputStream(); 5 r&n  
//logResponseHead(httpConnection); %I%OHs  
\7 *"M y*  
;:w0%>X^  
byte[] b = new byte[1024]; T<u QhPMw  
int nRead; 1u_< 1X3  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) '2S?4Z  
{ p</V_BIW  
nStartPos += fileAccessI.write(b,0,nRead); Uc]sWcR  
//if(nThreadID == 1) `& ]H`KNa  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y;>D"C..  
} j55OG~)  
o/I`L  
*|3G"B{w6  
Utility.log("Thread " + nThreadID + " is over!"); dZ,~yV  
bDownOver = true; tP|ox]  
//nPos = fileAccessI.write (b,0,nRead); Xm~N Bt  
} %j;mDR9 5  
catch(Exception e){e.printStackTrace ();} K,f- w2!  
} SG-Xgr@  
} h`V#)Q  
i0{sE  
b|u0a6  
//打印回应的头信息 q,.@<sW  
public void logResponseHead(HttpURLConnection con) Y| F~w~Cb  
{ t ;bU#THM  
for(int i=1;;i++) f^@D uI  
{ kD_616  
String header=con.getHeaderFieldKey(i); L9,O,f  
if(header!=null) k'-5&Q  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (aSY.#;  
Utility.log(header+" : "+con.getHeaderField(header)); _F tI2G9  
else U3M;6j9`  
break; =.t3|5U8  
} >VB*Xt\C&  
} !2]'S=Y  
})5I/   
Ydh+iLjhx  
public void splitterStop() DM3 %+ xY  
{ 7H_*1_%ZQ  
bStop = true; xt X`3=s  
} yMKVF`D*  
t@3y9U$  
w8(z\G_0  
} E)Cdw%}^  
[D<"qT^*z6  
?9:~d#p  
/* 2D ' $  
**FileAccess.java 3 UG UZ  
*//文件访问(定位,写) U$wD'v3pw  
package NetFox; t}f,j^`e  
import java.io.*; ~cb7]^#u1l  
"\l#q$1h  
,2Q5'!o  
public class FileAccessI implements Serializable{ i5Dq'wp  
9"b  =W@  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9{XV=a v  
RandomAccessFile oSavedFile; uN9J?j*ir  
long nPos; ,?`Zrxe[  
3s$vaV~(a  
9<-7AN}Z  
public FileAccessI() throws IOException L3'$"L.|u  
{ Xx e07J~  
this("",0); 3 cF4xUIZ  
} 6~!l7HqO  
+$\/HO  
m"RSDM!  
public FileAccessI(String sName,long nPos) throws IOException !6l}s$1i|  
{ P,={ C6*  
oSavedFile = new RandomAccessFile(sName,"rw"); ja+PVf  
this.nPos = nPos; ]r(s02  
oSavedFile.seek(nPos); aW;DfH  
} L_Lhmtm}m  
@agxu-Y  
KU*XRZu)  
public synchronized int write(byte[] b,int nStart,int nLen) Q;y)6+VU4  
{ 3u~V&jl  
int n = -1; HCZVvsG  
try{ G)3Q|Vc  
oSavedFile.write(b,nStart,nLen); P|QM0GI  
n = nLen; 4~Jg\@  
} J @^Ypq  
catch(IOException e) #B!<gA$/  
{ tlpTq\;  
e.printStackTrace (); JbXd9AMh2  
} ^H~g7&f9?N  
8Ao pI3  
W|AK"vf  
return n; GVld]ioycG  
} agp7zw=N  
],l\HHQ  
=a!_H=+4  
} \<W/Z.}/  
F6gU9=F1<  
'QC'*Hl  
/* 87yZd8+)  
**SiteInfoBean.java Rh#QPYPq  
*/ M992XXd  
package NetFox; )h`8</#m{  
MWJ}  
e^yfoE<7  
public class SiteInfoBean { b&2 N7%  
L^x h5{  
w,eW?b  
private String sSiteURL; //Site's URL Y>SpV_H%  
private String sFilePath; //Saved File's Path xt1Ug~5  
private String sFileName; //Saved File's Name ,j e  
private int nSplitter; //Count of Splited Downloading File e)*-<AGwC  
QyD(@MFxb  
Ff&kK5} q  
public SiteInfoBean() kV@?Oj.&I,  
{//nSplitter的缺省值为5 AfvIzsT0  
//default value of nSplitter is 5 sny$[!)  
this("","","",5); U%rq(`;  
} H_FT%`iM  
;C,t`(  
JiFB<Q\  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &.[I}KH|B  
{ <7_s'UAL!  
sSiteURL= sURL; ?ZP@H _w6}  
sFilePath = sPath; 2U@:.S'K  
sFileName = sName; =hi{J M  
this.nSplitter = nSpiltter; qijQRxS  
,Rdw]O  
!24PJ\~I  
} o^v]d7I8b  
Nj=0bg"Qg5  
z^u*e  
public String getSSiteURL() /B)`pF.n  
{ YT}ZLx  
return sSiteURL; lx:.9>  
} V@r V +s  
BKKW3PT  
[,sm]/Xlc  
public void setSSiteURL(String value) "P yG;N!W  
{ cy0j>-z  
sSiteURL = value; VWrb`p@  
} mv>-XJ+  
Scfe6+\EW  
</!GU*  
public String getSFilePath() E?S  
{ ^j7>Ul,  
return sFilePath; aRy" _dZ2  
} |J$ Bj?  
Egmp8:nZl@  
^J'O8G$  
public void setSFilePath(String value) %#TAz7  
{ DdqE6qE  
sFilePath = value; xM=?ES  
} lQ&J2H<w  
&Gs/#2XQ  
~rlPS#]o  
public String getSFileName() !GnwE  
{ g[ N3jt@  
return sFileName; Dg*'n  
} QY c/f"9  
W:hTRq  
E8L\3V4  
public void setSFileName(String value) lUd4`r"  
{ [*1:?mD$  
sFileName = value; M)3'\x :  
} )v\ A8)[  
'm0_pM1:D  
y+h/jEbM</  
public int getNSplitter() Yf_/c*t\5  
{ m-]F]c=)w<  
return nSplitter; p ^ ONJL  
} o_a'<7\#i  
eW;c 3<  
r4Xaa<  
public void setNSplitter(int nCount) S 9|^VU  
{ Mavid kS  
nSplitter = nCount; M[P1hFuna  
} .rQcg.8/B  
} N?IdaVLj  
}Z)YK}_1  
wRg[Mu,Q5  
/* e!vWGnY  
**Utility.java Zn:]?%afdO  
*/ kQ"Ax? b  
package NetFox; dF7`V J2  
W&HxMi  
(_AU)  
public class Utility { z9w]{Zd_,d  
poy_?7G  
ZEs^b  
public Utility() m -0}Pe9L  
{ mQ3gp&d3W  
sl`?9-_[  
~( :$c3\  
} KQ ^E\,@o  
b^A7R{G7  
//线程睡眠 2 SU  
public static void sleep(int nSecond) Bf;<3k)5.  
{ 1n[wk'}qf4  
try{ a:s$[+'Y  
Thread.sleep(nSecond); {4*5Z[  
} udPLWrPF\  
catch(Exception e) pm2]  
{ ra8AUj~RX  
e.printStackTrace (); $3xDjiBb  
} *0m|`- T  
} q#K0EAgC  
mR$0Ij/v  
//日志 |h6, .#n  
public static void log(String sMsg) vhzz(UPUt  
{ !Wj`U$];  
System.err.println(sMsg); jOZ>^5}  
} w$j6!z  
_&[-< cu  
%qEp{itq  
public static void log(int sMsg) rNICK2Ah  
{ 1Se2@WR'  
System.err.println(sMsg); (:R5"|]@<x  
} fi%lN_Ev?  
} tMXNi\Bj  
4{G>T  
GK1P7Qy?V  
/* =i6k[rg  
**TestMethod.java OS1f}<  
*/ _+Z5qUmQ  
package NetFox; ^CD? SP"i  
[E/. r{S  
> w SI0N  
public class TestMethod { n4.\}%=z  
HkY#i;%N  
i-. AD4  
public TestMethod() V."cmtf  
{ ///xx/weblogic60b2_win.exe v=cX.^ L  
try{ 5g.K yj|  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g ;X K3R  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); GyV uQ51  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?1r<`o3l\  
fileFetch.start(); eI%k xqc  
} &q M8)2Y  
catch(Exception e){e.printStackTrace ();} (M{>9rk8  
. BX*C  
3QF[@8EH{  
} &8I*N6p:%/  
_C19eW'  
T7o7t5*  
public static void main(String[] args) q s:TR  
{ C=2DxdZG  
new TestMethod(); bf.yA:~U  
} 7 0EH~  
} wOLV?Vk  
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
批量上传需要先选择文件,再选择上传
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八