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
  • 10592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 P{xMB#1h  
**SiteFileFetch.java L'aMXNO  
*/ =_^g]?5i  
package NetFox; JYv&It  
import java.io.*; pM(y?zGt  
import java.net.*; X@~sIUXx9  
_x UhDu%  
De>pIN;B>  
public class SiteFileFetch extends Thread { (]7@0d88  
ya:H{#%6  
B@iIj<p~  
SiteInfoBean siteInfoBean = null; //文件信息Bean -F8%U:2a  
long[] nStartPos; //开始位置 >W-e0kkH  
long[] nEndPos; //结束位置 ARQ1H0_B  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 k;LENB2iv  
long nFileLength; //文件长度 y:2o-SJn  
boolean bFirst = true; //是否第一次取文件 0 |F (qR  
boolean bStop = false; //停止标志 g^0  
File tmpFile; //文件下载的临时信息 3>L1}zyM]  
DataOutputStream output; //输出到文件的输出流 Jt)<RMQ^R  
=WO{h48]  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) A=XM(2{aN  
public SiteFileFetch(SiteInfoBean bean) throws IOException kY_UY~E  
{ ?|s[/zPS=  
siteInfoBean = bean; j<l>+., U  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); .-WCB  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Uj!L:u2b  
if(tmpFile.exists ()) &Q&$J )0  
{ JRodYXjE  
bFirst = false; IgFz[)  
read_nPos(); \H" (*["&  
} 7kJ,;30)  
else G53!wIW2:  
{ b%)a5H(  
nStartPos = new long[bean.getNSplitter()]; pAa{,,Qc  
nEndPos = new long[bean.getNSplitter()]; VFYJXR{  
} eGguq~s`  
D~mGv1t"  
w^ DAu1  
aX~iY ~?_  
} ]h|GaHiE  
DH 9?~|  
$}\. )^[}  
public void run() Wg$MKc9Vy[  
{ SQz>e  
//获得文件长度 $hEX,  
//分割文件 :^ cA\2=  
//实例FileSplitterFetch UhEnW8^bz1  
//启动FileSplitterFetch线程 gqC:r,a  
//等待子线程返回 ^T<<F}@q  
try{ wiFckF/  
if(bFirst) 3gGF?0o  
{ `[:f;2(@  
nFileLength = getFileSize(); |5FyfDaFBX  
if(nFileLength == -1) HZP`u >.  
{ EL+}ab2S  
System.err.println("File Length is not known!"); n=yFw\w'  
} bF}~9WEa  
else if(nFileLength == -2) /sYD+*a  
{ M&>Z[o  
System.err.println("File is not access!"); Qp< 6qM35  
} y t<K!=7&  
else J@)6]d/,  
{ a"ht\v}1  
for(int i=0;i<nStartPos.length;i++) U9;AU] A  
{ 7d9%L}+q  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); my*/MC^O  
} YxsW Y7J  
for(int i=0;i<nEndPos.length-1;i++) e <IT2tv>u  
{ (IEtjv}D  
nEndPos = nStartPos[i+1]; ,I)/ V>u  
} TYB^CVSZ  
nEndPos[nEndPos.length-1] = nFileLength; 2>UyA.m0  
} /gPn2e;  
} FfP Ce5)  
u/``*=Y@  
ffSecoX  
//启动子线程 hDfsqSK0 /  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^TDHPBlG  
for(int i=0;i<nStartPos.length;i++) ,H.q%!{h_  
{ h"q`gj  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >-]Y%O;}  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #Ok*O r  
nStartPos,nEndPos,i); j4Lf6aUOX  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Cj ykM])  
fileSplitterFetch.start(); &%INfl>o7.  
} nC2A&n&>  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4Kx;F 9!%~  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~KCOCtiD  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U*,5t81  
nEndPos = " + nFileLength); RELLQpz3  
// fileSplitterFetch[nPos.length-1].start(); 7]G3yt->  
$7lI Dt  
iGm[fxQ|  
//等待子线程结束 e >MC 3D`5  
//int count = 0; rbs:qLa%  
//是否结束while循环 qM]eK\q 1  
boolean breakWhile = false; lB3W|-Ci  
ci|6SaY*  
Lymy/9  
while(!bStop) rr2|xL?+u  
{ wD"Y1?Mr  
write_nPos(); -Vw,9VCF  
Utility.sleep(500); @R>J\>  
breakWhile = true; nKufVe  
K^w(WE;db  
t|d9EC]c(  
for(int i=0;i<nStartPos.length;i++)  s y#CR4X  
{ IU/dY`J1  
if(!fileSplitterFetch.bDownOver) vA:1z$m  
{ $^d,>hJi  
breakWhile = false; WOR~tS  
break; 0I& !a$:  
} b`fPP{mG  
} a\aJw[d{  
if(breakWhile) h0d;a  
break; yw$er?  
TDk'  
-AJe\ J 2  
//count++; ;ukwKf s  
//if(count>4) Hj$JXo[U  
// siteStop(); ?nCG:\&;'=  
} 8?h-H #h  
E"nIC,VZ  
+A3@{ 2  
System.err.println("文件下载结束!"); K1]H~'  
} tJ i#bg%  
catch(Exception e){e.printStackTrace ();} % sbDH  
} STL&ZO  
a9`E&Q}z  
2 D>WIOX  
//获得文件长度 fOtL6/?  
public long getFileSize() u-$(TyDEl|  
{ 3g`uLA X>u  
int nFileLength = -1; 1c8 J yp  
try{ I_oJx  
URL url = new URL(siteInfoBean.getSSiteURL()); 8lg $]  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nM>oG'm[n  
httpConnection.setRequestProperty("User-Agent","NetFox"); OV_Y`u7YR  
n GZZCsf <  
yL7D;<!S&  
int responseCode=httpConnection.getResponseCode(); 4U*J{''L  
if(responseCode>=400) mADq_` j  
{ py6|uGN  
processErrorCode(responseCode); d dkh*[  
return -2; //-2 represent access is error x$tx!%,)/S  
} xlZ"F  
@bSxT,2  
8vOKm)[%  
String sHeader; NiQ`,Q$B  
6-c3v  
]v{f!r=}  
for(int i=1;;i++) l\I#^N  
{ *BF5B\[r?  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $e)d!m.  
//Utility.log(in.readLine()); =* oFs|v  
sHeader=httpConnection.getHeaderFieldKey(i); TL-sxED,,D  
if(sHeader!=null) oi^2Pvauh  
{ e C?adCb  
if(sHeader.equals("Content-Length")) XCc /\  
{ $vlq]6V8  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); mEyJ o|  
break; 8D@H4O.  
} /7/d u[P6  
} d!mtSOh  
else '/trM%<  
break; "l&=a1l  
} Ue^2H[zs-  
} {7.."@Ob<v  
catch(IOException e){e.printStackTrace ();} $hZb<Xz  
catch(Exception e){e.printStackTrace ();} 7 p}J]!Z  
EnnT)qos  
qpjtF'  
Utility.log(nFileLength); Vf9PHHH|   
e33j&:O  
VJmX@zX9  
return nFileLength; mrX 2w  
} GVhO}m  
1BO$xq  
1RpTI7  
//保存下载信息(文件指针位置) rH Et]Xa  
private void write_nPos() :iqFC >D  
{ G5a PjP  
try{ 6;6a.iZ  
output = new DataOutputStream(new FileOutputStream(tmpFile)); "Ah (EZAR  
output.writeInt(nStartPos.length); ARvT  
for(int i=0;i<nStartPos.length;i++) a$H*C(wL  
{ Z M_ 6A1  
// output.writeLong(nPos); 2[6>h)  
output.writeLong(fileSplitterFetch.nStartPos); &D0suK#  
output.writeLong(fileSplitterFetch.nEndPos); ChO?Lm$y  
} g S xK9P  
output.close(); H'7AIY }  
} HxCq6Y_m<  
catch(IOException e){e.printStackTrace ();} v'gP,UO-%D  
catch(Exception e){e.printStackTrace ();} Ww-%s9N<  
} :ZG^`H/X1d  
k]?M^jrm  
GO0Spf_Gh  
//读取保存的下载信息(文件指针位置) |TM&:4D]^  
private void read_nPos() `2`Nu:r^  
{ Rj6:.KEJ  
try{ ~_<I}!j/B  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); tVVnQX  
int nCount = input.readInt(); hd{Vz{;W  
nStartPos = new long[nCount]; 7yp7`|,p  
nEndPos = new long[nCount]; q,6 y{RyS  
for(int i=0;i<nStartPos.length;i++) W _j`'WN/  
{ C/V{&/5w  
nStartPos = input.readLong(); ? g9mDe;k  
nEndPos = input.readLong(); uis;S)+  
} :a$ZYyD  
input.close(); Q-;ltJ  
} tTrUVuZ  
catch(IOException e){e.printStackTrace ();} cfI5KLG~#  
catch(Exception e){e.printStackTrace ();} pgT XyAP{  
} $T7hY$2Q l  
ZK,}3b{  
B198_T!  
private void processErrorCode(int nErrorCode) wXw pKm  
{ !#cZ!  
System.err.println("Error Code : " + nErrorCode); 18JhC*in  
} F%QZe*m[  
SjgF&LD  
09?n5x!6  
//停止文件下载 eveGCV;@  
public void siteStop() Ij; =  
{ @?ntMh6  
bStop = true; XgY( Vv  
for(int i=0;i<nStartPos.length;i++)  yH_L<n  
fileSplitterFetch.splitterStop(); +SCUS]  
T{=.mW^ x  
86d *  
} BOqq=WY  
} aIaydu+\  
//负责部分文件的抓取 KI(9TI *  
**FileSplitterFetch.java "h.}o DS  
*/ ~:7AHK2  
package NetFox; *]G&pmMs  
)Y':u_Lo  
: sIZ+3  
import java.io.*;  v|+}>g  
import java.net.*; Fs_,RXW"  
( 8+_~_  
 (2vR8  
public class FileSplitterFetch extends Thread { BcV;EEi  
n =v4m_e  
w7\:S>;(O"  
String sURL; //File URL v8g3]MVj3  
long nStartPos; //File Snippet Start Position u:H@]z(x  
long nEndPos; //File Snippet End Position 6w{^S~rqo  
int nThreadID; //Thread's ID Bu?"b=B*  
boolean bDownOver = false; //Downing is over <LM<,  
boolean bStop = false; //Stop identical 3}O.B r|  
FileAccessI fileAccessI = null; //File Access interface i gzISYC_  
&8t?OpB =h  
=!NYvwg6;o  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException R`=IYnoOA  
{ lv9Ss-c4  
this.sURL = sURL; E&0A W{  
this.nStartPos = nStart; :6LOb f\01  
this.nEndPos = nEnd; M64zVxsd  
nThreadID = id; R =HN>(U  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @t`| w.]ml  
} #I9|>XE1  
0 O4'Ts ?  
2a*1q#MpAt  
public void run() 'T[=Uuj"  
{ js Tb0  
while(nStartPos < nEndPos && !bStop) 1DcYc-k#  
{ +Cx~4zEq  
wbI(o4rXE  
RhyI\(Z2q  
try{ 9\TvX!)h  
URL url = new URL(sURL); 4s*P5w_'/  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); aq"E@fb  
httpConnection.setRequestProperty("User-Agent","NetFox"); )<4o"R:*  
String sProperty = "bytes="+nStartPos+"-"; GSV,  
httpConnection.setRequestProperty("RANGE",sProperty); T,(IdVlJ  
Utility.log(sProperty); d T/*O8  
'.~vN L+ O  
0<{/T*AU:  
InputStream input = httpConnection.getInputStream(); ,)V*xpp  
//logResponseHead(httpConnection); `{I,!to  
=Z/'|;Vd_x  
;~z>GJox  
byte[] b = new byte[1024]; -a3+C,I8g  
int nRead; P;KbS~ SlC  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]Ke|wRQD  
{ `(;d+fof  
nStartPos += fileAccessI.write(b,0,nRead); &0f7>.y  
//if(nThreadID == 1) /(n)I  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L3q)j\ ls  
} ~2@U85"o  
~QBf78@Gf  
 g/+M&k$  
Utility.log("Thread " + nThreadID + " is over!"); O,qR$#l   
bDownOver = true; o)}b Fw  
//nPos = fileAccessI.write (b,0,nRead); pRc(>P3;  
} 9Lz)SYd  
catch(Exception e){e.printStackTrace ();} { KwLcSn  
} o~P8=1t   
} 8f^URN<x  
U YUIpe  
ec1g7w-n  
//打印回应的头信息 8SAz,m!W)  
public void logResponseHead(HttpURLConnection con) K 1:F{*  
{ $6!`  
for(int i=1;;i++) AaTtY d  
{ ' 1P_*  
String header=con.getHeaderFieldKey(i); 8x,;B_Zu  
if(header!=null) " "a+Nc  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); tY# F8a&  
Utility.log(header+" : "+con.getHeaderField(header)); mSQ!<1PM  
else $<s@S;Ri  
break; T>f-b3dk  
} l'16B^  
} w5|@vB/pj  
sef!hS06  
{z F  
public void splitterStop() n+uq|sYVa  
{ bMSF-lQ  
bStop = true; gP1$#KgU  
} KMbBow3o*~  
_%1.D0<~-E  
5,Q('t#J  
} (/*-M]>  
;4qalxzu  
N,[M8n,  
/* uDoSe^0  
**FileAccess.java ["L?t ^*G  
*//文件访问(定位,写) *;gi52tM  
package NetFox; m9e$ZZG$  
import java.io.*; q"5 2-42  
$(CHwG-  
D3^v[>E2  
public class FileAccessI implements Serializable{ in+`zfUJ9  
czZ-C +}%  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7L<oWAq  
RandomAccessFile oSavedFile; k2+Z7#2n  
long nPos; El+]}D"  
\uPT-M*  
rW6w1  
public FileAccessI() throws IOException Xif`gb6`  
{ [FCNW0NV  
this("",0); V&}Z# 9Dx  
} 9n%W-R.  
s~63JDy"E  
?b7vc^E&  
public FileAccessI(String sName,long nPos) throws IOException %vThbP#mR|  
{  /KV@Ce\  
oSavedFile = new RandomAccessFile(sName,"rw"); *l9Y]hinq  
this.nPos = nPos; ?PQiVL  
oSavedFile.seek(nPos); ]D]K_`!K  
} v0xi(Wu  
'V>+G>U  
oDP|>yXC)  
public synchronized int write(byte[] b,int nStart,int nLen) \Q)~'P3  
{ 7SM/bJ-M#  
int n = -1;  9q5[W=|  
try{ G?V3lQI1n  
oSavedFile.write(b,nStart,nLen); p_nrua?  
n = nLen; d)AkA\neWo  
} J *B`C^i  
catch(IOException e) 07MLK8jS  
{ zld>o3K}  
e.printStackTrace (); 6x7=0}'  
} 'qD9k J`  
UM]wDFn'E  
VuR BJ2D  
return n; z&:[.B   
} h}d7M55#|  
Umd!j,  
EtcamI*`  
} rTJWftH!  
+Q9HsfX/  
?t"PawBWE  
/* 2#[Y/p  
**SiteInfoBean.java oe<Y,%u"6  
*/ @rF\6I  
package NetFox; WT)")0)[  
2u:j6ic  
G@'0vYb#  
public class SiteInfoBean { h ^c'L=dR  
Ij8tBT?jlL  
5C&f-* Bh  
private String sSiteURL; //Site's URL i_@RWka<  
private String sFilePath; //Saved File's Path S .jjB  
private String sFileName; //Saved File's Name Rju8%FRO  
private int nSplitter; //Count of Splited Downloading File  %!S  
ig,|3(  
w\ :b(I  
public SiteInfoBean() O o:jP6r  
{//nSplitter的缺省值为5 _7<U[63  
//default value of nSplitter is 5 P:TpB6.=q  
this("","","",5); ]3,0 8JW=  
} q  ha1b$  
2I<T<hFW]  
@rMW_7[y  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) C"{on%  
{ g2]-Q.  
sSiteURL= sURL; 1sJN^BvuG  
sFilePath = sPath; NZuFxJ-`  
sFileName = sName; Y<+4>Eh  
this.nSplitter = nSpiltter; e2fct|'  
o~K2K5I  
:I('xVNPz  
} Uk9g^\H<D  
(n/1 :'  
fz3*oJ'  
public String getSSiteURL() Mvv=)?:  
{ sdWl5 "  
return sSiteURL; jh G7sS|  
} qrc/Q;$  
l/^-:RRNKi  
uH[0kh  
public void setSSiteURL(String value) 3Y-v1.^j  
{ <3 }l8Z  
sSiteURL = value; W wha?W>  
} 0 l@P]_qq`  
-/%jeDKp  
`1@[uWl  
public String getSFilePath() +d f?N  
{ [R>   
return sFilePath; cloI 6%5r  
} CE,O m^  
sCQup^\  
E+zn\v  
public void setSFilePath(String value) .M2&ad :  
{ L@r.R_*H?s  
sFilePath = value; |sa7Y_  
} HW72 6K*  
PEEY;x  
7V (7JV<>  
public String getSFileName() (dF;Gcw+  
{ g{hA,-3  
return sFileName; }dJ ~Iy  
} %n25Uq  
zI!R-Nb  
QV$dKjMS  
public void setSFileName(String value) p0y?GNQ  
{ K)&XQ`&  
sFileName = value; xm5FQ) T  
} P &0cF{  
\)ZX4rs{8  
O^weUpe\  
public int getNSplitter() NB5B$q_'#  
{ 3b@1Zahz  
return nSplitter; #0^3Wm`X;  
} 8'"/gC{  
[KI`e  
-#;VFSz,9*  
public void setNSplitter(int nCount) *9Js:z7I  
{ MZW Y  
nSplitter = nCount; f^sb0nU  
} Y~hd<8 ~  
} )^S^s >3  
h$ iyclX  
W?J*9XQ`  
/* ;To+,`?E;q  
**Utility.java OXX(OCG>  
*/ >m6,xxTR  
package NetFox; R 4QwWSBJ  
LY!3u0PnlT  
=tRe3o0(  
public class Utility { :$Q]U2$mPS  
5uJP) S?  
i^cM@?  
public Utility() 1fhK{9#  
{ 7K]U |K#  
`pAp[]SfQd  
VE"0 VB.  
} `) !2E6 =  
VfC[U)w*vm  
//线程睡眠 C\ 2 >7  
public static void sleep(int nSecond) %3#I:>si  
{ :mV7)oWH  
try{ xVz -_z  
Thread.sleep(nSecond); >`?+FDOJ,  
} 'j<:FUDJ  
catch(Exception e) ^_S-s\DW  
{ f+aS2k(e>  
e.printStackTrace (); ~v(M6dz~vk  
} OK2/k_jXN'  
} 9q)nNX<$)  
l)rvh#D  
//日志 q,,>:]f#  
public static void log(String sMsg) -anFt+f-  
{ 0e:QuV2X  
System.err.println(sMsg); {p*hNi)0  
} yZ~eLWz  
5nM9!A\D  
v6DxxE2n  
public static void log(int sMsg) {{[jC"4AY  
{ p5# P r  
System.err.println(sMsg); %f> |fs  
} 3|'#n[3  
} cM<hG:4%wX  
MHr0CYyb.  
60~>f)vu  
/* ;'Vipj   
**TestMethod.java 6=g]Y!o$  
*/ T.w}6? 2  
package NetFox; 7k#${,k  
fF9oYOh|  
e<O;pM:  
public class TestMethod { oB{}-[G  
kSDa\l!W]  
id#k!*$7  
public TestMethod() sg6w7fp>  
{ ///xx/weblogic60b2_win.exe vrm{Ql&  
try{ Va/@#=,q]  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6aF'^6+a  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b6WC @j`*T  
SiteFileFetch fileFetch = new SiteFileFetch(bean); o~.o^0Y  
fileFetch.start(); F<oc Y0=9p  
} y%IG:kZ,  
catch(Exception e){e.printStackTrace ();} leb^,1/D6  
*/5<L99v  
5Du>-.r  
} )*TW\v`B  
c2\rjK   
nzE,F\k  
public static void main(String[] args) Z*vpQBbu  
{ 1y)$[e   
new TestMethod(); +zVcOS*-  
} k}f<'g<H  
} b!^M}s6  
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
温馨提示:欢迎交流讨论,请勿纯表情、纯引用!
认证码:
验证问题:
10+5=?,请输入中文答案:十五