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
  • 8319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
/* v=-3 ,C  
**SiteFileFetch.java \RyA}P5 S  
*/ #q.G_-H4J@  
package NetFox; b)^ZiRW``  
import java.io.*; u?Mu*r?  
import java.net.*; $OoN/^kv  
[qMdOY%jx  
? 4Juw?  
public class SiteFileFetch extends Thread { 2_b'mepV  
%v:h]TA  
K/ m)f#  
SiteInfoBean siteInfoBean = null; //文件信息Bean ^T6!z^g1h  
long[] nStartPos; //开始位置 FD+PD:cQn  
long[] nEndPos; //结束位置 TFDCo_>o  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 L b;vrh;A  
long nFileLength; //文件长度 wN hR(M7  
boolean bFirst = true; //是否第一次取文件 >ImM~SR)  
boolean bStop = false; //停止标志 1t=X: ]0j  
File tmpFile; //文件下载的临时信息 aZGDtzNG5h  
DataOutputStream output; //输出到文件的输出流 ,GP4I3D  
f<p4Pkv  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) <>Ddxmw  
public SiteFileFetch(SiteInfoBean bean) throws IOException `h5eej&s(  
{ L#q9_-(#  
siteInfoBean = bean; ?QT"sj64w  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); HTyF<K  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ~7WXjVZ  
if(tmpFile.exists ()) \+Ln~\Sv  
{ ]Ja8i%LjOG  
bFirst = false; w?W e|x3  
read_nPos(); :P~& b P  
} ^6y4!='ci  
else B&k T#  
{ G2{M#H  
nStartPos = new long[bean.getNSplitter()]; Cy:`pYxhd  
nEndPos = new long[bean.getNSplitter()]; @Qjl`SL%O^  
} m{dyVE  
(jMAa%  
^J~A+CEf"W  
TM}'XZ&  
} P`I G9  
(,c?}TP  
M2P@ &  
public void run() ]O=S2Q  
{ aX'g9E  
//获得文件长度 ww t()  
//分割文件 jNG?2/P6&  
//实例FileSplitterFetch 1(7.V-(G  
//启动FileSplitterFetch线程 s_Oh >y?Aq  
//等待子线程返回 3]OP9!\6  
try{ bNpIC/#0K  
if(bFirst) D6)Cjc>a  
{ S*m`'  
nFileLength = getFileSize(); + >gbZ-S  
if(nFileLength == -1) nf.:5I.  
{ 3_*Xk. .d  
System.err.println("File Length is not known!"); Etc?;Z[F#  
} (X_,*3Yxk  
else if(nFileLength == -2) .>64h H  
{ &}6ES{Nr8  
System.err.println("File is not access!"); hi D7tb=g~  
} m|2]lb  
else $< K)fbG  
{ P[GX}~_k  
for(int i=0;i<nStartPos.length;i++) G1;'nwf}  
{ ) UDJ[pL@  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 2]aZe4H.  
} x+y!P  
for(int i=0;i<nEndPos.length-1;i++) nHA`B.:B  
{ }8F$& AFt  
nEndPos = nStartPos[i+1]; "i{_<;p O  
} >yA,@%X  
nEndPos[nEndPos.length-1] = nFileLength; ^8oc^LOa~2  
} KWh M  
} -wRyMY_ D  
+>WC^s  
qz=#;&ZU  
//启动子线程 1'v!9  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; keQXJ0  
for(int i=0;i<nStartPos.length;i++) S|q!? /jqj  
{ U|Z>SE<k  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ')u5l  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P 5qa:<  
nStartPos,nEndPos,i); 9oz(=R  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,D@ ;i  
fileSplitterFetch.start(); (4 /]dTb  
} W93JY0Ls9|  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !` M;#  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3q|cZQK!1  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >4|c7z4  
nEndPos = " + nFileLength); lKV\1(`  
// fileSplitterFetch[nPos.length-1].start(); k BiBXRt  
1ntkM?  
!V]MLA`  
//等待子线程结束 L;--d`[  
//int count = 0; N;x<| %peL  
//是否结束while循环 i2FD1*=/?  
boolean breakWhile = false; q1TW?\pjb:  
P"bknXL  
.mT#%ex  
while(!bStop) txml*/zL  
{ \>Ga-gv6/  
write_nPos(); 5@UC c  
Utility.sleep(500); 5rfH;`  
breakWhile = true; ]/o12pI  
Jny)uo8  
Zc%foK{  
for(int i=0;i<nStartPos.length;i++) P!FEh'.  
{ RrO0uadmn  
if(!fileSplitterFetch.bDownOver) Q$3\ /mz  
{ 77xq/c[)  
breakWhile = false; i[2bmd!H  
break; `*" H/QG  
} (zs4#ja2,  
} 0eqi1;$b]  
if(breakWhile) pM&]&Nk  
break; b'7z DZI]  
|k`f/*  
*,W!FxJ  
//count++; c/<Sa|'  
//if(count>4) 9|N" @0<B  
// siteStop(); R81{<q'%X  
} 5@+4  
crJ7pe9  
f2O*8^^Y{Q  
System.err.println("文件下载结束!"); qY$*#*Q  
} ?E+:]j_  
catch(Exception e){e.printStackTrace ();} O}K_l1  
} -t@y\vZF,  
Q%& _On  
WxVn&c\  
//获得文件长度 xb9Pc.A[  
public long getFileSize() &o*s !u  
{ t;.^K\S4  
int nFileLength = -1; @K$VV^wp  
try{ UCn*UX  
URL url = new URL(siteInfoBean.getSSiteURL()); h"%|\o+3  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yV:EK{E  
httpConnection.setRequestProperty("User-Agent","NetFox"); %XP_\lu]  
D!bKm[T  
GJ1;\:cQq  
int responseCode=httpConnection.getResponseCode(); d~{jEg  
if(responseCode>=400) KE/-VjZu  
{ ?$|uT  
processErrorCode(responseCode); W\@?e32  
return -2; //-2 represent access is error gDQkn {T.%  
} .D8~)ZWN  
aO.\Qe+j  
w4e%-Ln  
String sHeader; h4CTTe)  
=tr1*s{  
RzA2*]%a  
for(int i=1;;i++) E`Jp(gK9F  
{ &W=V%t>Z  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {OB-J\7Y  
//Utility.log(in.readLine()); +}_Pf{MW  
sHeader=httpConnection.getHeaderFieldKey(i); ,vPe}OKj  
if(sHeader!=null) m:)Z6  
{  4%g6_KB  
if(sHeader.equals("Content-Length")) P%zH>K  
{ )7&42>t  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {&2$[g=[ ^  
break; p?+lAbe6H  
} Sa3I?+  
} vk  @%R  
else 1)TK01R8  
break; $%7I:  
} 8tb6 gZz  
} M{`/f@z(  
catch(IOException e){e.printStackTrace ();} :s'o~   
catch(Exception e){e.printStackTrace ();} q} ]'Q -  
j/)"QiS*?  
JDLTOLG  
Utility.log(nFileLength); &w+;N5}3  
slU  
ic%?uWN  
return nFileLength; .6>  hD1'  
} i 8l./Yt/  
XB0a dp  
j?EskT6  
//保存下载信息(文件指针位置) h ?uqLsRl  
private void write_nPos() 06 QU  
{ Ho 3dsh)  
try{ duX0Mc. 0P  
output = new DataOutputStream(new FileOutputStream(tmpFile)); FH)t:!#  
output.writeInt(nStartPos.length); sK+ (v  
for(int i=0;i<nStartPos.length;i++) 86 *;z-G  
{ Q*]$)D3n  
// output.writeLong(nPos); C>.e+V+':  
output.writeLong(fileSplitterFetch.nStartPos); ?2{bKIV_  
output.writeLong(fileSplitterFetch.nEndPos); "r u]?{v  
} /:bKqAz;M  
output.close(); e# t3u_  
} \[:PykS  
catch(IOException e){e.printStackTrace ();} *yJ[zXXjJ  
catch(Exception e){e.printStackTrace ();} l^.K'Q1~a  
} kr%2w  
XC=%H'p  
pX@Si3G`  
//读取保存的下载信息(文件指针位置) !RS9%ES_?  
private void read_nPos() h@=7R  
{ puOC60zI  
try{ K*~]fy  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2@vJ  
int nCount = input.readInt(); n5|l|#c$N  
nStartPos = new long[nCount]; COR;e`%,  
nEndPos = new long[nCount]; `>s7M.|X  
for(int i=0;i<nStartPos.length;i++) M :V2a<!c  
{ -K"4rz  
nStartPos = input.readLong(); oizT-8i@N  
nEndPos = input.readLong(); c! @F  
} U#bl=%bF  
input.close(); zbNA \.y  
} dm6~  
catch(IOException e){e.printStackTrace ();} Z1M>-[j)  
catch(Exception e){e.printStackTrace ();} Frk cO  
} "NDxgJ%J35  
X 7=fX~s  
7|YN:7iA  
private void processErrorCode(int nErrorCode) $(ewk):  
{ U[R@x`  
System.err.println("Error Code : " + nErrorCode); 9M_(He -  
} Z`Pd2VRp  
6SVqRD<`  
6xoq;=o  
//停止文件下载 'n0 .#E_  
public void siteStop() d6`OXTD  
{ -T7xK/  
bStop = true; 4[TR0bM%  
for(int i=0;i<nStartPos.length;i++) 9Y/L?km_(  
fileSplitterFetch.splitterStop(); b;#\~( a  
3o*FPO7?  
btH _HE  
} c"7j3/p  
} _d@=nK)  
//负责部分文件的抓取 Bn?:w\%Ue  
**FileSplitterFetch.java YzAFC11,  
*/ Po(]rQbE  
package NetFox; 9GgA6#  
NBjeH tT  
@b2`R3}9R  
import java.io.*; c8{]]  
import java.net.*; YD\]{,F|  
*:_P8G;  
Q/ZkW  
public class FileSplitterFetch extends Thread { vfcb:x  
jij<yM8$g  
; dd Q/  
String sURL; //File URL S_v(S^x6  
long nStartPos; //File Snippet Start Position `Gd$:qV  
long nEndPos; //File Snippet End Position !g>.i`  
int nThreadID; //Thread's ID ]u#JuX  
boolean bDownOver = false; //Downing is over &.Q8Mi aT  
boolean bStop = false; //Stop identical ymWgf 6r<  
FileAccessI fileAccessI = null; //File Access interface ;;Ds  
{fV}gR2  
:m'+tGs  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vMla'5|l  
{ NOt@M  
this.sURL = sURL; T@[!A);  
this.nStartPos = nStart; f?56=& pHY  
this.nEndPos = nEnd; K=?VDN  
nThreadID = id; RKZ6}q1n  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x0Yse:RE^  
} S[,8TErz  
|.P/:e9  
 Fl3#D7K  
public void run() WKmbNvN^  
{ "w_N' -}#  
while(nStartPos < nEndPos && !bStop) -"Q-H/qh  
{ 9 [jTs3l:  
5,pSg  
%zeATM[`  
try{ C`V)VJM  
URL url = new URL(sURL); _q?<at}y  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); % UZVb V  
httpConnection.setRequestProperty("User-Agent","NetFox"); ^j)BKD-  
String sProperty = "bytes="+nStartPos+"-"; K93p"nHN  
httpConnection.setRequestProperty("RANGE",sProperty); ]"~51HQZ  
Utility.log(sProperty); X"q!Y#)  
w$|l{VI  
bU54-3Ox*  
InputStream input = httpConnection.getInputStream(); hWo=;#B*  
//logResponseHead(httpConnection); ]3Dl)[R  
,xI%A, (,;  
;heHefbvvd  
byte[] b = new byte[1024]; x;\wY'  
int nRead; 28andfl  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) gNpJ24QK  
{ ;WU<CKYG*  
nStartPos += fileAccessI.write(b,0,nRead); >dzsQ^Nj  
//if(nThreadID == 1) E7zm{BX]  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Bi3+)k>u7  
} Pw0Ci  
?=;qK{)37  
^Q+i=y{W  
Utility.log("Thread " + nThreadID + " is over!"); i/So6jW  
bDownOver = true; ]@^coj[  
//nPos = fileAccessI.write (b,0,nRead); Xz 4 x  
} lb*8G  
catch(Exception e){e.printStackTrace ();} ww k PF  
} KvPX=/&Zu  
} H ?M/mGP  
=PHIpFIuk  
B;K`q  
//打印回应的头信息 IJIzXU  
public void logResponseHead(HttpURLConnection con) zTbVp8\pI  
{ C0*@0~8$9  
for(int i=1;;i++) hsKmnH@#  
{ `Y=WMNy  
String header=con.getHeaderFieldKey(i); *Vw\'%p*  
if(header!=null) 8qEK+yi,  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Rli:x  
Utility.log(header+" : "+con.getHeaderField(header)); A@*:<Hs%  
else efP&xk  
break; '3IC*o"  
} mqff]m  
} K+=+?~  
>wHxmq8F5<  
k>jbcSY(z<  
public void splitterStop() _ee dBpV  
{ 7Q w|!  
bStop = true; 6x)$Dl  
} !R-z%  
s@hRqGd:  
] b9-k  
} -u!FOD/  
`1OgYs  
2lKV#9"  
/* ?E%ELs_Dl  
**FileAccess.java C:8_m1Y{  
*//文件访问(定位,写) :,b iyJt  
package NetFox; {gNV[45  
import java.io.*; 1?*  
0 [?ny`Y  
[YrHA~=U  
public class FileAccessI implements Serializable{ &N~ZI*^  
UO*Ymj 1  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [%Bf< J<  
RandomAccessFile oSavedFile; :j')E`#   
long nPos; &!aAO(g  
}]n$ %g (  
+ Q=1AXe  
public FileAccessI() throws IOException `LAR@a5i  
{ l {jmlT  
this("",0); ?{w3|Ef&  
} -Y Bd, k3  
Uy ?  
;w|b0V6  
public FileAccessI(String sName,long nPos) throws IOException ]lw|pvtd  
{ AcI,N~~  
oSavedFile = new RandomAccessFile(sName,"rw"); VvFC -r,=G  
this.nPos = nPos; l\M_-:I+4  
oSavedFile.seek(nPos); DrnJ;Hi"  
} 7QKr_  
/ N) W2  
8t@p @Td|  
public synchronized int write(byte[] b,int nStart,int nLen) "H -"  
{ \<}&&SuH  
int n = -1; f7h*Vu`>  
try{ /!^&;$A'  
oSavedFile.write(b,nStart,nLen); X U/QA [K  
n = nLen; c|F[.;cR  
} Le<w R  
catch(IOException e) :1t~[-h^  
{ 3d<HN6&U  
e.printStackTrace (); L-B<nl  
} M?&h~V1OI~  
|#1(Z-}  
C2Xd?d  
return n; jM-)BP6f4  
} &E xYXI  
l]~n3IK"  
"S 3wk=?4  
} V[-jD8=' 3  
lEHzyh}2k  
:l|%17N  
/* '47P|t  
**SiteInfoBean.java *(PL _/:  
*/ &Ysosy*  
package NetFox; |6=p{ y  
xI>A6  
HB Iip?  
public class SiteInfoBean { l;y7]DO  
>.dWjb6t  
vSi_t K4  
private String sSiteURL; //Site's URL '* \|; l#1  
private String sFilePath; //Saved File's Path zC _<(4$-"  
private String sFileName; //Saved File's Name TuW%zF/  
private int nSplitter; //Count of Splited Downloading File rx (2yf  
N3u((y/  
>#,G}xf  
public SiteInfoBean() 6JKqn~0Kk  
{//nSplitter的缺省值为5 PJcwH6m  
//default value of nSplitter is 5 G$ _yy:  
this("","","",5); s'kDk2r  
} }%Bl>M  
^v.,y3  
@?YRuwp L  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) vjjSKP6B  
{ )(y) A[  
sSiteURL= sURL; pb#?l6x$+  
sFilePath = sPath; r5!/[_l  
sFileName = sName; CHV*vU<N  
this.nSplitter = nSpiltter; kcb.Wz~=  
JyR/1 W  
}Tf9S<xpq3  
} p~*UpU8u  
71vkyn@"  
-V:"l  
public String getSSiteURL() !S&L*OH,  
{ Bz5-ITX   
return sSiteURL; $Y5)(  
} o.q/O)'V u  
:n /@z4#  
|&Ym@Jyj  
public void setSSiteURL(String value) 6252N]*  
{ f4L`.~b'hb  
sSiteURL = value; TEDAb >  
} rj6#1kt  
$H+VA@_  
e["2QIOe  
public String getSFilePath() H,N)4;F<c  
{ =m5SK5vLKT  
return sFilePath; gn3jy^5  
} Nbp!teH6  
-?(E_^ng  
r#xg#uoj  
public void setSFilePath(String value) )Tk1 QHU  
{ 6;|n]m\Vd  
sFilePath = value; ]O]GeAGC2  
} ;vt8R=T  
M`ip~7"  
Yv:55+e!|  
public String getSFileName() y#XbJuN/  
{ }#X8@  
return sFileName; _x!7}O#k  
}  A^p[52`  
|g=="  
qL,tYJ<m%  
public void setSFileName(String value) wC5ee:u C%  
{ 1UKg=A-q  
sFileName = value; CZ nOui  
} $z+8<?YD  
I_A@BnM{I  
Yot?=T};3{  
public int getNSplitter() D$T%\ P  
{ 6P';DB  
return nSplitter;  Br` IW  
} tO0!5#-VR  
[H=)  
W^s ;Bi+Nw  
public void setNSplitter(int nCount) )n,P"0  
{ (&!NC[n,  
nSplitter = nCount;  4._( |  
}  |jM4E$  
} Dgy]ae(Hb3  
[ :zO}r:  
K# Jk _"W  
/* F{UP;"8'  
**Utility.java e @IA20  
*/ 3;a<_cE*@  
package NetFox; }Q";aU0^  
zL\OB?)5J  
*6} N =Z  
public class Utility { VO"("7L  
1bH;!J  
D:Zy  
public Utility() X$yN_7|+  
{ 3"O>&Q0c  
U4cY_p?  
&8z[`JW,T  
} Z ,EvQ8i  
/ 4lvP  
//线程睡眠 d'Zqaaf k%  
public static void sleep(int nSecond) '7oA< R  
{ ,u/aT5\_  
try{ 435;Vns\n  
Thread.sleep(nSecond); 9ksE>[7  
} 2Y7)WPn  
catch(Exception e) +=:#wzK@  
{ # 0Lf<NZ  
e.printStackTrace (); ;s52{>&F]  
} _%GGl$kH  
} /IsS;0K%L  
.j-IX1Sa  
//日志 {6}eN|4~#  
public static void log(String sMsg) IV)<5'v  
{ I6Ce_|n ?k  
System.err.println(sMsg); lIProF0  
} #es9d3 ~\  
SXy=<%ed  
F}=aBV|-  
public static void log(int sMsg) w08?DD]CDt  
{ G8;w{-{m  
System.err.println(sMsg); S*n@81Z  
} 0A( +ZMd  
} :duo#w"K  
=dFv/F/RW  
W]nSR RWco  
/* X@f "-\  
**TestMethod.java $ mI0Bk  
*/ \.3D~2cU  
package NetFox; tQylT0'[+o  
0q'w8]m  
L>YU,I\o  
public class TestMethod { qBCK40   
Dre]AsgiV  
rf$X>M=G  
public TestMethod() rp0ZvEX  
{ ///xx/weblogic60b2_win.exe +gLPhX:`  
try{ ? 8LXP  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4vwTs*eB `  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Rb{U+/gq  
SiteFileFetch fileFetch = new SiteFileFetch(bean); et }T %~T  
fileFetch.start(); [AW" D3  
} R[;z X(y  
catch(Exception e){e.printStackTrace ();} V#`fs|e;y  
K5XK%Gl"  
IhA*"  
} Oj^,m.R  
Q_Gi]M9  
s%W<dDINl  
public static void main(String[] args) sx`O8t  
{ QV&D l_  
new TestMethod(); 3l#IPRn9AO  
} uxzze~_+C  
} P<f5*L#HD  
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:
3+5=?,请输入中文答案:八 正确答案:八