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
  • 7504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
/* ~>j5z&:&  
**SiteFileFetch.java z0yPBt1W  
*/ l\Q--  
package NetFox; W8@o7svrh  
import java.io.*; M%U1?^j8  
import java.net.*; .B9i`)0  
| Ns-l (l  
E`M, n ,  
public class SiteFileFetch extends Thread { R#K,/b%SV  
C0 RnBu  
KOYU'hw  
SiteInfoBean siteInfoBean = null; //文件信息Bean p3Ey[kURp  
long[] nStartPos; //开始位置 z2/E?$(  
long[] nEndPos; //结束位置 V2v}F=  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 j'2:z#  
long nFileLength; //文件长度 s-S#qGZ  
boolean bFirst = true; //是否第一次取文件 bhqV2y*'  
boolean bStop = false; //停止标志 a 8(mU%  
File tmpFile; //文件下载的临时信息 +NM`y=@@  
DataOutputStream output; //输出到文件的输出流 3Z taj^v  
pA~eGar_J  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) +\Zr\fOe|%  
public SiteFileFetch(SiteInfoBean bean) throws IOException j\/Rjn+:[  
{ "DpgX8lG_  
siteInfoBean = bean; D^\gU-8M  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); rV5QKz6'  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); gwAZ2w  
if(tmpFile.exists ()) `dGcjLs Iz  
{ PQ}owEJ2eM  
bFirst = false; eG\|E3Cb9  
read_nPos(); rAuv`.qEV  
} r_p4pxs  
else nQHQVcDs8  
{ 54^2=bp  
nStartPos = new long[bean.getNSplitter()]; OG!+p}yD]  
nEndPos = new long[bean.getNSplitter()]; %UO ;!&K  
} Z(~v{c %<  
dPVl\<L1  
HZ_,f"22  
M%aA1!@/  
} E U# M.  
3|Vh[iAa\  
v\#1&</qd^  
public void run() gO9\pI 2  
{ K:<0!C!  
//获得文件长度 :m{;<LRV  
//分割文件 #_U[ T  
//实例FileSplitterFetch 5nQxVwY  
//启动FileSplitterFetch线程 %]KOxaf_z  
//等待子线程返回 >3,t`Z:  
try{ 9 M<3m  
if(bFirst) _d J"2rx  
{ ;oT!\$Mu  
nFileLength = getFileSize(); +eIX{J\s  
if(nFileLength == -1) $Fr>'H+i  
{ f,s1k[w/;  
System.err.println("File Length is not known!"); }zE Qrfl  
} S0zk<S  
else if(nFileLength == -2) v ?OIK=Xm  
{ p10i_<J]=  
System.err.println("File is not access!"); ]Av)N6$&-Z  
} C8oAl3d+h  
else 5(qc_~p^  
{ iN]#XIQ%  
for(int i=0;i<nStartPos.length;i++) b-Uy&+:X*d  
{ |s}7<A  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); `%5~>vPS  
} /W @k:  
for(int i=0;i<nEndPos.length-1;i++) o4l=oY:'  
{ |PY*"Ul  
nEndPos = nStartPos[i+1]; V']{n7a-  
} J Gpy$T{t  
nEndPos[nEndPos.length-1] = nFileLength; e5HHsR6  
} '(.vB~m7*+  
} `;\<Fr  
dJYW8pcKT  
{] Zet}2  
//启动子线程 % a9C]?  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (vXes.|+t  
for(int i=0;i<nStartPos.length;i++) V39`J*fI  
{ D( YNa  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :OFL@byS  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wgV?1S>Z  
nStartPos,nEndPos,i); 7c7:B2Lq  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !#' y#  
fileSplitterFetch.start(); IFd2r;W8  
} >AUj4d  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &i8UPp%  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'U %L\v,  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )V6<'>1WZ  
nEndPos = " + nFileLength); 6Y 4I $[  
// fileSplitterFetch[nPos.length-1].start(); k >aWI  
o$[alh;c+W  
D?Y j5eOa  
//等待子线程结束 A]WR-0Z7  
//int count = 0; ZR"BxE0_k  
//是否结束while循环 _(&XqEX  
boolean breakWhile = false; \'}? j-8  
+|OrV'  
NR@n%p  
while(!bStop) "A0J~YvYWJ  
{ gb clk~kX  
write_nPos(); A@HCd&h  
Utility.sleep(500); ]"DsZI-glW  
breakWhile = true; ]|#%`p56  
FfET 45"l  
<lxE^M  
for(int i=0;i<nStartPos.length;i++) c7[+gc5}  
{ JS:AHJSz  
if(!fileSplitterFetch.bDownOver) ^XbN&'^,HL  
{ l^"HcP6  
breakWhile = false; zK@DQ5  
break; s+jL BY  
} 9bVPMq7}i  
} U$+G9  
if(breakWhile) rERHfr`OU  
break; ySXQn#}-,  
`dpm{s n  
OY?x'h  
//count++; ]!=,8dY  
//if(count>4) k#Bq8d  
// siteStop(); N-Jp; D  
} teDO,$  
%I 3D/!%  
z:+fiJB_  
System.err.println("文件下载结束!"); gWZzOH*  
} Bf-KCqC".  
catch(Exception e){e.printStackTrace ();} CPj8`kl  
} A['0~tOP  
4#c-?mh_  
WdvXVF  
//获得文件长度 Vr1yj  
public long getFileSize()  zG0191f  
{ q8 _8rp-@  
int nFileLength = -1; xD|CQo}:  
try{ N)tqjq  
URL url = new URL(siteInfoBean.getSSiteURL()); <Jwx|  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >I^_kBa  
httpConnection.setRequestProperty("User-Agent","NetFox"); [fjP.kw;J  
( ;(DI^Un8  
Tz"Xm/Gy  
int responseCode=httpConnection.getResponseCode(); JJ=%\j  
if(responseCode>=400) 7B"*< %<  
{ $Z2Y%z6y  
processErrorCode(responseCode); [$bK%W{f  
return -2; //-2 represent access is error UW?(-_8  
} `ywI+^b  
(TjY1,f!H  
ztRe\(9bL  
String sHeader; ),u)#`.l G  
(aQNe{D#  
},W<1*|  
for(int i=1;;i++) X\yy\`o  
{ 4sCzUvI~Y1  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Dno'-{-  
//Utility.log(in.readLine()); `uN}mC!r]  
sHeader=httpConnection.getHeaderFieldKey(i); 3{j&J-  
if(sHeader!=null) )^^Eh=Kbj  
{ $afE= qC*  
if(sHeader.equals("Content-Length")) PAUepO_  
{ {"x>ewAf  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &LD=Zp%  
break; 9BA*e-[  
} }bZcVc2  
} !eH9LRp  
else #F~^m  
break; ~g_]Sskf7  
} 4* vV9*'!  
} x%WL!Lo  
catch(IOException e){e.printStackTrace ();} +"HLx%k  
catch(Exception e){e.printStackTrace ();} F}C.F  
{@7{!I|eD  
s,*kWy"jp  
Utility.log(nFileLength); 0kp#+&)+  
>cE@m=[  
.e,(}_[[<  
return nFileLength; A3#^R%2)W  
} cp&- 6 w+  
@-ms_Z  
UDUj  
//保存下载信息(文件指针位置) wj$J} F  
private void write_nPos() {}W9m)I  
{ U~)i&":sN  
try{ Y4 <  
output = new DataOutputStream(new FileOutputStream(tmpFile)); XC D&Im  
output.writeInt(nStartPos.length); -hpJL\ng  
for(int i=0;i<nStartPos.length;i++) Q#2gjR r  
{ ;<9dND  
// output.writeLong(nPos); (i"@{[IP  
output.writeLong(fileSplitterFetch.nStartPos); WN+D}z]  
output.writeLong(fileSplitterFetch.nEndPos); c@]_V  
} sr*3uI-)L  
output.close(); "kHQ}#6r  
} rphfW:  
catch(IOException e){e.printStackTrace ();} zxV,v*L)  
catch(Exception e){e.printStackTrace ();} rz  
} b;;C><  
Cqy)+x_OQ,  
VX`E7Sf!}  
//读取保存的下载信息(文件指针位置) iLyJ7zby  
private void read_nPos() 6u'+#nm  
{ X4D>  
try{ 8!T6N2O6d  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]0+5@c  
int nCount = input.readInt(); x<S?"  
nStartPos = new long[nCount]; 5dPPm%U{  
nEndPos = new long[nCount]; lg(*:To3B  
for(int i=0;i<nStartPos.length;i++) .YT&V  
{ =y>g:}G7  
nStartPos = input.readLong(); 0CTUcVM#9  
nEndPos = input.readLong(); E[Rd= /P6  
} sUki|lP  
input.close(); "/O`#Do/  
} Pz/bne;=  
catch(IOException e){e.printStackTrace ();} ,dG2[<?o  
catch(Exception e){e.printStackTrace ();} %O! ~!'  
} <![]=~z $  
S\F;b{S1  
)G a%Eg9  
private void processErrorCode(int nErrorCode) _Kw<4 $0<p  
{ &f:"p*=a\  
System.err.println("Error Code : " + nErrorCode); '4L0=G:A<q  
} me7?   
S S/9fT"[  
)Hp{8c  
//停止文件下载 JS&=V 67[  
public void siteStop() +a{P,fRl@  
{ :ziV3jRM  
bStop = true; l.V{H<v}  
for(int i=0;i<nStartPos.length;i++) o!";&\,Ip  
fileSplitterFetch.splitterStop(); 8l, R|$RKP  
W 6d[v/+K+  
_9^  
} K)z! e;r  
} R`_RcHY:  
//负责部分文件的抓取 YCWt%a*I'  
**FileSplitterFetch.java |@rPd=G^(/  
*/ ep<O?7@j-G  
package NetFox; bm &$wf  
vp4l g1/  
[xTu29X.  
import java.io.*; mihR *8p  
import java.net.*; +~E;x1&'  
p\7(`0?8VN  
w=]bj0<A=  
public class FileSplitterFetch extends Thread { D]{#!w(d  
?dJ[? <aG  
Y\Z.E ;  
String sURL; //File URL rhLm2q  
long nStartPos; //File Snippet Start Position y(#Aze{yC  
long nEndPos; //File Snippet End Position <vP{U  
int nThreadID; //Thread's ID \5MW65  
boolean bDownOver = false; //Downing is over )_|;h2I  
boolean bStop = false; //Stop identical tqnvC UIE  
FileAccessI fileAccessI = null; //File Access interface bpQ5B'9  
r&u&$ "c  
}bW"Z2^nB  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !c;Z<@  
{ #i8] f{  
this.sURL = sURL; K%+[2Hj2  
this.nStartPos = nStart; q13bV  
this.nEndPos = nEnd; 8: x{  
nThreadID = id; Q*W`mFul  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Y"x9B%e  
} KqM!7  
[SFX;v!9  
9L$bJO-3  
public void run() 8f""@TTp  
{ JDQ7  
while(nStartPos < nEndPos && !bStop) 7_HJ|QB  
{ Y5 BWg  
O0"u-UX{  
: J3_g<@  
try{ LSR{N|h+)  
URL url = new URL(sURL); }# ~DX!Sj  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Fp_?1 y  
httpConnection.setRequestProperty("User-Agent","NetFox"); sS 5aJ}Qs  
String sProperty = "bytes="+nStartPos+"-"; Ik4FVL8~  
httpConnection.setRequestProperty("RANGE",sProperty); hzT,0<nw  
Utility.log(sProperty); O% 1X[  
?k5m1,fHW  
^""Ss  
InputStream input = httpConnection.getInputStream(); r+4<Lon~  
//logResponseHead(httpConnection); N^)\+*tf1  
d)_fI*:f  
BrWo/1b  
byte[] b = new byte[1024]; XM9}ax  
int nRead; 'zEmg}  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !)Y T_ib  
{ X ^ ?M4  
nStartPos += fileAccessI.write(b,0,nRead); r#% e$  
//if(nThreadID == 1) $jpAnZR- /  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J=%(f1X<W  
} 20Umjw.D  
[VD)DO5  
i'[o,dbE  
Utility.log("Thread " + nThreadID + " is over!"); 0|RFsJ"  
bDownOver = true; [&tN(K9*  
//nPos = fileAccessI.write (b,0,nRead); r )EuH.z  
} cc*xHv^  
catch(Exception e){e.printStackTrace ();} ?89K [D|  
} Rxg ^vM*  
} l*v6U'J  
TA2?Ia;@xV  
t_VF=B^LuR  
//打印回应的头信息 _(qU%B  
public void logResponseHead(HttpURLConnection con) !| G 8b'  
{ \Ax[/J2aO  
for(int i=1;;i++) "kS(b4^  
{ 8?YWE62  
String header=con.getHeaderFieldKey(i); U{8]TEv  
if(header!=null) %ut^ O  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -f{NVX\<0  
Utility.log(header+" : "+con.getHeaderField(header)); ~ AU!Gm.  
else }i)^?@  
break; 4Jf6uhaE  
} h#Z5vH  
} .L#xX1qr  
@@?P\jv~  
bv%A;  
public void splitterStop() %,Pwo{SH  
{ ySS kw7  
bStop = true; "_g3{[es!  
} 9d\B*OU  
U2lDTRt  
55mDLiA  
} l"C)Ia&/  
m(B,a,g<  
*/T.]^  
/* eJ=K*t|  
**FileAccess.java /^m3?q[a  
*//文件访问(定位,写) _o'3v=5T  
package NetFox; [K*>W[n  
import java.io.*; `4@_Y<  
lZt{L0  
Y$@?Y/rhR  
public class FileAccessI implements Serializable{ z_A:MoYf o  
g9rsw7  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B{In "R8  
RandomAccessFile oSavedFile; &!adW@y  
long nPos; ;;*'<\lP.j  
Q>G lA  
1L4-hYtCj  
public FileAccessI() throws IOException ^:(:P9h  
{ Ykt{]#  
this("",0); 5S;|U&f|  
} H.n+CR  
}Q=@$YIesD  
"TLY:V  
public FileAccessI(String sName,long nPos) throws IOException n#NE.ap$&,  
{ ?HsQ417.H  
oSavedFile = new RandomAccessFile(sName,"rw"); ]]InD N  
this.nPos = nPos; 7AOjlC9R}  
oSavedFile.seek(nPos); XDot3)2`  
} "!fvEE  
Qd{h3K^hlu  
uTX0lu;  
public synchronized int write(byte[] b,int nStart,int nLen) Nydhal00  
{ &3o[^_Ti  
int n = -1; FtEmSKD  
try{ 7jf%-X  
oSavedFile.write(b,nStart,nLen); DKvNQ:fI>9  
n = nLen; 6G6B!x  
} f19~B[a  
catch(IOException e) ssWSY(j]  
{ x}c%8dO#J  
e.printStackTrace (); F1q a`j^'  
} *<5zMSZO  
W=$cQ(x4Z  
SviGLv;oR  
return n; #nzVgV]  
}  .L vg $d  
bsn.HT"5  
/.Fvl;!J;  
} ,pg\5b  
$PNS`@B  
JyfWy  
/* d{gj8  
**SiteInfoBean.java ~<)CI0=  
*/ >_<J=8|E  
package NetFox; OE"r=is  
=VctG>ct|  
\0^ZNa?  
public class SiteInfoBean { f:).wi Ld  
v4YY6? 4  
<21@jdu3n,  
private String sSiteURL; //Site's URL y{`aM(&  
private String sFilePath; //Saved File's Path Wl4T}j  
private String sFileName; //Saved File's Name c^$+=-G{fd  
private int nSplitter; //Count of Splited Downloading File (I) e-1  
E>|xv#:~DV  
}+" N '  
public SiteInfoBean() ?11\@d  
{//nSplitter的缺省值为5 4raKhN"  
//default value of nSplitter is 5 CQ(;L{}  
this("","","",5); xIrRFK9[Q  
} 8%Wg;:DZx  
;`TSu5/  
3 E~d  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3XOf-v:~  
{ 4Y=sTXbFt  
sSiteURL= sURL; y*AB=d^  
sFilePath = sPath; h /.^iT  
sFileName = sName; B!#F!Wk"  
this.nSplitter = nSpiltter; X`,]@c%C`  
Ga%x(1U[&  
,z*-93H1  
} Gz>M`M`[4  
]Q%|69H}B  
syseYt]  
public String getSSiteURL() Yy_o*Ozq  
{ nCj_4,O  
return sSiteURL; 9aE.jpN  
} T\Zq/Z\  
|.s#m^"  
TDMyZ!d  
public void setSSiteURL(String value) WC?}a^ 8  
{ 'A|OVyH  
sSiteURL = value; e2onR~Cf  
} H"_]Hq  
q*h1=H52  
:=0XT`iY  
public String getSFilePath() nhUL{ER  
{ ^J([w~&  
return sFilePath; uAWmg8  
} gEE6O%]g  
o*L#S1yL  
e-taBrl;  
public void setSFilePath(String value) kH)JBx.  
{ +>F #{b  
sFilePath = value; ,sM>{NK 9R  
} ,w+}Evp])  
%?4 G^f  
HfF4BQxm  
public String getSFileName() #*g.hL<  
{  `#m>3  
return sFileName; 9O%4x"*PO  
} )ny,vcU]  
Rj/9\F3H  
L 1fK  
public void setSFileName(String value) V?k"BU  
{ OZw<YR  
sFileName = value; 7\q_^  
} E rf$WPA  
05|,-S  
wc-ll&0Z  
public int getNSplitter() aWLeyXsAu  
{ h%hE$2  
return nSplitter; I& `>6=)  
} 'k9?n)<DW  
~vCfMV[F  
S[TJ{ L(  
public void setNSplitter(int nCount) `f@VX :aL}  
{ ~okIiC]#  
nSplitter = nCount; xELnik_L2  
} Kp|#04]  
} . k6)  
H& #Od?  
yrDWIU(8;6  
/* ZU vA`   
**Utility.java m-SP#?3  
*/ u% ^Lu.l_c  
package NetFox; DIk\=[{2q  
=,aWO7Pz  
5X7kZ!r  
public class Utility { !f(aWrw7e6  
S;o U'KOY  
)$#r6fQO  
public Utility() iwHy!Vi-5  
{ _HT*>-B  
/12D >OK  
I6]|dA3G  
} [\hk_(}  
*>=vSRL0_  
//线程睡眠 ]~,V(K  
public static void sleep(int nSecond) L"i B'=  
{ u5f+%!p  
try{ x 5u.D^  
Thread.sleep(nSecond); cx]O#b6B.  
} ZKG S?z  
catch(Exception e) Tl#Jf3XY}  
{ XFeeNcqF  
e.printStackTrace (); M y:9  
} CS 7"mE`{  
}  s*gyk  
Dm@wTt8N(  
//日志 XUD/\MoV  
public static void log(String sMsg) ub "(,k P  
{ s$Il;  
System.err.println(sMsg); 3:$hC8  
} !b O8apn  
7'[C+/:  
tQ7DdVdix  
public static void log(int sMsg) gT K5z.]  
{ hT&,5zaWdv  
System.err.println(sMsg); (D'Z4Y  
} 5 zlgmCGow  
} guC/eSxv  
9T47U; _)  
GHHErXT\a  
/* qYg4H|6  
**TestMethod.java WgdL^PN(h  
*/ 9Z0(e!b4S  
package NetFox; U~8.uldnF  
S9Fg0E+J  
w;.'>ORC  
public class TestMethod { ZQvpkO7}M  
>G2o  
u7u8cVF  
public TestMethod() 1#AdEd[  
{ ///xx/weblogic60b2_win.exe _nR8L`l*z  
try{ TEZ^Ia  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o~ .[sn5l-  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); W{Cc wq  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Kp *nOZ  
fileFetch.start(); (o_fY.  
} >4a@rT/  
catch(Exception e){e.printStackTrace ();} &XosDt  
A>6 b 6  
pti`q )  
} 9i)E<.6  
\ ?[#>L4  
3,j)PKf ;  
public static void main(String[] args) -OpI,qyS  
{ 4#uWj ?u  
new TestMethod(); $Yt29AQ  
} ,\;;1Kq  
} 'Y+AU#1~H  
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:
3+5=?,请输入中文答案:八 正确答案:八