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
  • 11850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
/* @l@erCw@  
**SiteFileFetch.java =.6JvX<d1*  
*/ _iZ9Ch\  
package NetFox; %8! }" Xa  
import java.io.*; ~d&W;mef-  
import java.net.*; ]t.6bb4  
cp3O$S  
Aw7_diK^  
public class SiteFileFetch extends Thread { u*<knZ~ty  
J+f*D+x1  
G>j4b}e  
SiteInfoBean siteInfoBean = null; //文件信息Bean )\l(h%s[I  
long[] nStartPos; //开始位置 -i"?2gK  
long[] nEndPos; //结束位置 f _*F&-L  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 rL<a^/b/=  
long nFileLength; //文件长度 bjB4  
boolean bFirst = true; //是否第一次取文件 6e :#x:O  
boolean bStop = false; //停止标志 76 RFu@k  
File tmpFile; //文件下载的临时信息 94 GF8P  
DataOutputStream output; //输出到文件的输出流 LVxR *O  
Et+WLQ6)  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) fV5MI[ t  
public SiteFileFetch(SiteInfoBean bean) throws IOException C?7I(b:  
{ ^Z:qlYZ  
siteInfoBean = bean; *waaM]u  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); lb<D,&+  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 61&A`  
if(tmpFile.exists ()) 4Y4QR[>IU3  
{ n_MY69W  
bFirst = false; _Rm1-,3  
read_nPos(); GGkU$qp2~  
} M}xyW"yp  
else C *U,$8j|}  
{ cP`[/5R  
nStartPos = new long[bean.getNSplitter()]; q# t&\M.U  
nEndPos = new long[bean.getNSplitter()]; S3.76&  
} geSH3I   
}(Dt,F`  
@0U={qX  
h5VZ-v_j  
} F4 :#okt  
FR? \H"'x  
2H2Yxe7?-  
public void run() PNhxF C.  
{ [vyi_0[  
//获得文件长度 >}6V=r3[+  
//分割文件 5 p! rZ  
//实例FileSplitterFetch \ 3HB  
//启动FileSplitterFetch线程 _!Ir|j.A  
//等待子线程返回 ;A;FR3=)  
try{ $ {5|{`  
if(bFirst) !ui:0_  
{ IO}53zn<l  
nFileLength = getFileSize(); ><3!J+<?  
if(nFileLength == -1) D:vX/mf;7  
{ ~mK|~x01@  
System.err.println("File Length is not known!"); aXRf6:\%  
} $I:&5o i  
else if(nFileLength == -2) ~Rk ~Zn  
{ yZw5?{g@  
System.err.println("File is not access!"); ?'+ kZ|  
} t p<wMrq<  
else  mPS27z(  
{ \O(~:KN  
for(int i=0;i<nStartPos.length;i++) .<kbYo:MV  
{ P QA}_o  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 6PdLJ#LS  
} 6Dz N.fz  
for(int i=0;i<nEndPos.length-1;i++) )HJ#|JpxC  
{ :*dfP/GO  
nEndPos = nStartPos[i+1]; &_ W~d0  
} n|AV7c  
nEndPos[nEndPos.length-1] = nFileLength; p^THoF'~T  
} ,)%$Zxng  
} vG'I|OWg  
+X|^ ~)tMJ  
 "DsL$D2e  
//启动子线程 8q_"aa,`  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /7jb&f   
for(int i=0;i<nStartPos.length;i++) m%)Cw)t 7  
{ wC`+^>WFo  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %+0V0.  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), nX|]JW  
nStartPos,nEndPos,i); 9A!B|s  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =dDr:Y<@*  
fileSplitterFetch.start(); r0(*]K:.  
} ]o3K  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), EaUO>S  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |cIv&\ x  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8c^Hfjr0  
nEndPos = " + nFileLength); ^< wn  
// fileSplitterFetch[nPos.length-1].start(); $BUm,  
G7uYkJO  
bTbF  
//等待子线程结束 32x[6"T  
//int count = 0; hG8<@  
//是否结束while循环 83g$k 9lG.  
boolean breakWhile = false; s5 ($b  
crl"Ec  
^g N/5  
while(!bStop) \k>1q/T0V  
{ AtYqD<hl:  
write_nPos(); .-4]FGg3  
Utility.sleep(500); SBh"^q  
breakWhile = true; U2vM|7 ]VP  
jHQnD]Hr  
j`:D BO&)\  
for(int i=0;i<nStartPos.length;i++) DuI>z?bS  
{  /wT<p  
if(!fileSplitterFetch.bDownOver) J1g+H2  
{ U\GuCw  
breakWhile = false; ,4H/>yPw  
break; H?cJ'Q, 5  
} iph}!3f  
} ?'RB'o~  
if(breakWhile) t+Au6/Dx?  
break; |*n B2  
_:7:ixN[Ie  
kY^ k*-v  
//count++; ae0t *;~  
//if(count>4) (d>}Fp  
// siteStop(); DVz_;m6)  
} ODNZLCB~t  
gAr=fq-|  
Pmdf:?B  
System.err.println("文件下载结束!"); Q:U>nm>xA  
} hI 1or4V  
catch(Exception e){e.printStackTrace ();} Yaj}_M-  
} = :BTv[lv  
Z]08gH  
&>P<Zw-  
//获得文件长度 UU*v5&  
public long getFileSize() \- 8S"  
{ _o7t| pl~  
int nFileLength = -1; zEk /15  
try{ SW)jDy  
URL url = new URL(siteInfoBean.getSSiteURL()); A~({vb'  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zvK'j"Wq=  
httpConnection.setRequestProperty("User-Agent","NetFox"); D`R~d;U~  
SFR<T  
/ }Pj^^6A<  
int responseCode=httpConnection.getResponseCode(); z)Lw\H^/  
if(responseCode>=400) l KG' KR.  
{ ~'v9/I-"  
processErrorCode(responseCode); 7j8lhrM}^  
return -2; //-2 represent access is error * -(8Z>9  
} 6{!Cx9V  
se=;vp]3a  
Xm3r)Bm'3  
String sHeader; 4 (XV)QR  
qL4s@<|~  
7~Z(dTdSG  
for(int i=1;;i++) (0E<Fz V  
{ Jq?Fi'2F%  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); A DVUx}  
//Utility.log(in.readLine());  ZvwU  
sHeader=httpConnection.getHeaderFieldKey(i); Mj`g84  
if(sHeader!=null) 3,?LpdTS  
{ "x3x$JQZy  
if(sHeader.equals("Content-Length")) D)tL}X$  
{ 0.)q5B`  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )H(i)$I  
break; XAZPbvG|$  
} /j-c29nz  
} HD'adj_,  
else {2k]$|  
break; //'&a-%$^  
} +xd@un[r<  
} RM;Uq >l  
catch(IOException e){e.printStackTrace ();} =0a z5td  
catch(Exception e){e.printStackTrace ();} _L+j6N.h1  
BbiyyRa  
:b] \*  
Utility.log(nFileLength); \FIM'EKzu!  
X;n09 L`CB  
1,P\dGmu  
return nFileLength;  S~bhh&  
} C\4d.~C:w3  
BA[ uO3\4  
#p ;O3E@  
//保存下载信息(文件指针位置) #\ uB!;Q  
private void write_nPos() 4n"6<cO5q  
{ 6-z(34&N  
try{  aWPf3Q  
output = new DataOutputStream(new FileOutputStream(tmpFile)); b gxk:$E  
output.writeInt(nStartPos.length); 6j!idA!'  
for(int i=0;i<nStartPos.length;i++) udXzsY9Ng  
{ D?=4'"@v  
// output.writeLong(nPos); =R<92v  
output.writeLong(fileSplitterFetch.nStartPos); }2 Tq[rl~s  
output.writeLong(fileSplitterFetch.nEndPos); Fv*Et-8tN5  
} e_"m\e#N  
output.close(); D5!#c-Y-  
} f `D( V-4  
catch(IOException e){e.printStackTrace ();} 70'gVCb  
catch(Exception e){e.printStackTrace ();} -y>~ :.  
} 2Z5_@Y  
)|_L?q#w!'  
IEfYg(c0U  
//读取保存的下载信息(文件指针位置) {1qr6P,"  
private void read_nPos() 1[J|AkN  
{ JfY(};&  
try{  S'\e"w  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Npi) R)  
int nCount = input.readInt(); F]t=5 -O<  
nStartPos = new long[nCount]; KaX*) P  
nEndPos = new long[nCount]; P aeq  
for(int i=0;i<nStartPos.length;i++) g)R2V  
{ N6v?Qzvi  
nStartPos = input.readLong(); P*H0Hwn;  
nEndPos = input.readLong(); 1$+8wDVwad  
} @+l=R|  
input.close(); }LeS3\+UHl  
} ,`02fMOLc  
catch(IOException e){e.printStackTrace ();} TMo DN%{  
catch(Exception e){e.printStackTrace ();} T@*'}*  
} yM7Iq)o6u  
c& I  
&=MVX>[  
private void processErrorCode(int nErrorCode) N:+)6a  
{ I)yF!E &  
System.err.println("Error Code : " + nErrorCode); k~gOL#$  
} XK\3"`kd  
Oet+$ b  
.rITzwgB  
//停止文件下载 YYT#{>&  
public void siteStop() x NjQ"'i8  
{ [uK{``"  
bStop = true; }Z{FPW.QK  
for(int i=0;i<nStartPos.length;i++) #4lIna%VX  
fileSplitterFetch.splitterStop(); ]Vmo >  
gO)":!_n W  
)$1>6C\  
} CJER&"em7  
} k}p8"'O  
//负责部分文件的抓取 $dXx@6fP  
**FileSplitterFetch.java -jy0Kl/p  
*/ \=7jp|{Yl  
package NetFox; i/skU9  
1. +6x4%rV  
3h:y[Vm#9y  
import java.io.*; gnjhy1o  
import java.net.*; 7F6 B  
/`7+Gy<  
Mn/@?K?y  
public class FileSplitterFetch extends Thread { 'A^q)hpax  
[61*/=gWe  
2aX*|DGpw  
String sURL; //File URL f*B-aj#  
long nStartPos; //File Snippet Start Position yi*EobP  
long nEndPos; //File Snippet End Position ~D>pu%F  
int nThreadID; //Thread's ID KX]!yA  
boolean bDownOver = false; //Downing is over 3F@P$4!#l  
boolean bStop = false; //Stop identical Eh ";irE  
FileAccessI fileAccessI = null; //File Access interface $xbW*w  
#CaPj:>[  
PkI+z_  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException v&'#Gg  
{ q[C?1Kc .z  
this.sURL = sURL; 9O:l0 l  
this.nStartPos = nStart; x(vQ %JC  
this.nEndPos = nEnd; g27'il  
nThreadID = id; 9aY8`B  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 V^&*y+  
} 5.oIyC^Ik  
1kKfFpN  
*=2W:,$  
public void run() ~bx ev/$d  
{ 4|E^ #C  
while(nStartPos < nEndPos && !bStop) giX[2`^NG  
{ xsn=Ji2 F  
)?UoF&c/  
CDRbYO  
try{ {\(MMTQ  
URL url = new URL(sURL); gWGDm~+  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $q)YC.5$  
httpConnection.setRequestProperty("User-Agent","NetFox"); 4minzrKM\  
String sProperty = "bytes="+nStartPos+"-"; z&tC5]#  
httpConnection.setRequestProperty("RANGE",sProperty); @;tfHoXD  
Utility.log(sProperty); sHc-xnd  
(X,i,qK/  
xBA"w:<  
InputStream input = httpConnection.getInputStream(); )\=xPfs  
//logResponseHead(httpConnection); w+R7NFq  
>e>3:~&2  
6<<"9mxK  
byte[] b = new byte[1024]; (pd$?vRy  
int nRead; &<]f-  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [i /!ovcY  
{ H{vKk  
nStartPos += fileAccessI.write(b,0,nRead); lQHF=Jex  
//if(nThreadID == 1) X<}}DZSu a  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ly+UY.v"  
} ^ls@Gr7`P  
v62_VT2v  
Ze eV-  
Utility.log("Thread " + nThreadID + " is over!"); +h4W<YnW  
bDownOver = true; c\1X NPGG  
//nPos = fileAccessI.write (b,0,nRead); @%R4V[Lo.  
} n jWe^  
catch(Exception e){e.printStackTrace ();} 3X`9&0:j%  
} ?gl&q+mv  
} G/<zd)  
#BUq;5  
"mW'tm1+  
//打印回应的头信息 oNAnJ+_  
public void logResponseHead(HttpURLConnection con) igfQ,LWe!  
{ |(z{)yWbC[  
for(int i=1;;i++) b4e~Z  
{ oCa Ymi=:  
String header=con.getHeaderFieldKey(i); &sWr)>vs  
if(header!=null) p8~lGuH  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !%,7*F(  
Utility.log(header+" : "+con.getHeaderField(header)); {,Q )D$i  
else P3&s<mh  
break; ORs :S$Nt$  
} A _zCSRF,  
} BB/wL_=:  
i D IY|  
I?3b}#&V9  
public void splitterStop() KFd +7C9  
{ 7Ed0BJTa  
bStop = true; |l; Ot=C=  
} WzN c=@[W  
#T_!-;(Z  
#ODP+>-IjB  
} {fR\yWkt?  
0Idek  
]`&_!T  
/* h9H z6 >  
**FileAccess.java 4d@yAr}  
*//文件访问(定位,写) 5qtk#FB  
package NetFox;  j%Au0k  
import java.io.*; .[O{,r  
A*y4<'}<  
2d[q5p  
public class FileAccessI implements Serializable{ L/tpT?$fi  
?$f.[;mh  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4H-eFs%5  
RandomAccessFile oSavedFile; yxt"vm;  
long nPos; :W*yfhLt  
<T}U 3lL^  
L7C ;l,ot  
public FileAccessI() throws IOException s|Mo3_>  
{ |u>(~6  
this("",0); x.+T65X~4  
} h+Co:pr  
*/;7Uv7  
,TQec:B  
public FileAccessI(String sName,long nPos) throws IOException IgX &aW  
{ 6!m#;8 4  
oSavedFile = new RandomAccessFile(sName,"rw"); jq,M1  
this.nPos = nPos; m^3x%ENZ  
oSavedFile.seek(nPos); Te+(7 Z  
} *4U_MM#rX  
gZ,h9 5'  
|2j,  
public synchronized int write(byte[] b,int nStart,int nLen) = j1Jl^[  
{ >a?Bk4w  
int n = -1; v1OVrk>s>  
try{ fvC,P#z'|  
oSavedFile.write(b,nStart,nLen); Ss>pNH@ c  
n = nLen; |U|>YA1[b  
} J\@6YU[A  
catch(IOException e) d+q],\"R  
{ duY?LJ@g  
e.printStackTrace (); i/9iM\2  
} kW/G=_6  
RpivO,   
GTP'js  
return n; 6'Q{xJe?  
} <L-F3Buu  
x6UXd~ L e  
SOOVUMj  
} u<edO+  
WO qDW~  
a2Ak?W1  
/* g< j)  
**SiteInfoBean.java Z =+Z96  
*/ xe!bfzU  
package NetFox; 8fXiadP#  
!Y~UO)u2  
Y2r}W3F=  
public class SiteInfoBean { YRu@; `  
kB 8^v7o  
9J3fiA_  
private String sSiteURL; //Site's URL ?\V#^q-  
private String sFilePath; //Saved File's Path B6  0  
private String sFileName; //Saved File's Name e(0OZ_w  
private int nSplitter; //Count of Splited Downloading File Ehx9-*]  
<fUo@]Lv  
S^rf^%  
public SiteInfoBean() `8!9Fp  
{//nSplitter的缺省值为5 h=#w< @  
//default value of nSplitter is 5 ` B)@  
this("","","",5); _,J+b R+b  
} w2DC5ei'  
b#_RZ  
2ioHhcYdJU  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~>CvZ 7K  
{ G}nJ3  
sSiteURL= sURL; 7:jLZ!mgi  
sFilePath = sPath; {kpF etXt?  
sFileName = sName; z?o8h N\  
this.nSplitter = nSpiltter; X8)k'h  
4IeCb?  
=)Xj[NNRT  
} g:Hj1!'  
~:DL{ZeEb  
?:"ABkL|+Y  
public String getSSiteURL() 6 VEB2F  
{ cC/h7o dY  
return sSiteURL; jWrU'X  
} X)b$CG  
25SWIpgG  
4aXIRu%#7  
public void setSSiteURL(String value) 1/}H 0\9'  
{ =-U0r$sK+F  
sSiteURL = value; sO .MUj;  
} gm9*z.S\'  
0kE[=#'.'  
i7Qb~RW  
public String getSFilePath() KQ\K :#  
{ .#( vx;  
return sFilePath; Q-<]'E#\(  
} 6 5g ovor  
luoQ#1F?sl  
Aw#<:6-  
public void setSFilePath(String value) _uIS[%4g  
{ FZi@h  
sFilePath = value; Sm'Tz&!  
} h(|T.  
Z [!"x&H]h  
-#Zdf |  
public String getSFileName() 2K}49*  
{ w!f2~j~  
return sFileName; &;@L] o  
} "jL>P )  
X*2W4udF  
cH5i420;aO  
public void setSFileName(String value) f[o~d`z  
{ ',EI[ ]+  
sFileName = value; N~)-\T:ap  
} `zQuhD 8W  
Y1PR?c Q  
bzi"7%c  
public int getNSplitter() "Rj PTRe:  
{ s=8H< 'l  
return nSplitter; v) n-  
} f.6>6%l  
dNe!X0[  
iWCYK7c@.-  
public void setNSplitter(int nCount) )?rq8VO  
{ B>2R-pa4~  
nSplitter = nCount; ` Ig5*X4|  
} FV^jCseZ  
} 6`e{l+c=F  
_b&|0j:Ud  
~,)jZ-fw  
/* 6W i n!4  
**Utility.java d/d)MoaJ*t  
*/ iH(7.?.r  
package NetFox; {++ EX2  
a/J<(sak~X  
:c*"Dx'D  
public class Utility { 2-4N)q  
rq%]CsRY5  
Ju+3}  
public Utility() |*bUcS<S  
{ tq L(H25z  
"to!&@I| 4  
{nmG/dn {  
} # -'A =j  
MLDzWZ~}ef  
//线程睡眠 =KPmZ,/w  
public static void sleep(int nSecond) w"R<8e=  
{ %-n) L  
try{ Xh"9Bcjf  
Thread.sleep(nSecond); o#qdgZ  
} ](r}`u%}y  
catch(Exception e) Hx#YN*\.M  
{ ? }HK!feU  
e.printStackTrace (); j yHa}OT  
} b31$i 5{  
} w.m8SvS&b  
BE?]P?r?  
//日志 pCKP{c=6Q  
public static void log(String sMsg) -E7mt`:d  
{ _pdKcE\X  
System.err.println(sMsg); I\)`,w  
} KXt8IMP_"y  
%vmd2}dA  
Myc-lCE  
public static void log(int sMsg) P+CV4;Xz  
{ rNN>tpZ}  
System.err.println(sMsg); 8Ths"zwn  
} 5:@bNNX'j  
} \[G'cE  
ifn=De3+  
zhJeTctRz  
/* PD&e6;rj;  
**TestMethod.java H oQb.Z  
*/ }c,b]!:  
package NetFox; TEV DES  
#0AyC.\  
T}Tv}~!f  
public class TestMethod { 0,hs %x>v  
U%vTmdOY  
<'=!f6Wh  
public TestMethod() 971=OEyq*  
{ ///xx/weblogic60b2_win.exe \,;glY=M!  
try{ NO5k1/-  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W2{w<<\$3}  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `EKf1U\FI  
SiteFileFetch fileFetch = new SiteFileFetch(bean); +`>7cy%cZ  
fileFetch.start(); > .wZEQ6QK  
} 3Zp<#  
catch(Exception e){e.printStackTrace ();} <#0i*PM_  
+^7cS6"L  
!oz{XWE  
} UBd+,]"f  
0AM_D >fH  
w:zo \  
public static void main(String[] args) <K)]kf  
{ zjoo;(?D|  
new TestMethod(); J6#h~fpv  
} . X!!dx1<  
} S_7]_GQ9  
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
欢迎提供真实交流,考虑发帖者的感受
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八