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
  • 11954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
/* Tm3$|+}$f  
**SiteFileFetch.java _|tg#i|Om  
*/ ' {:(4>&  
package NetFox; `/+7@~[RU  
import java.io.*; j*xens$)  
import java.net.*; 4,<~t>M1  
^@[[,1"K  
2EK\QWo  
public class SiteFileFetch extends Thread { P9%9/ B:-  
]"CA P%  
mDV 2vg  
SiteInfoBean siteInfoBean = null; //文件信息Bean ^Gd <miw  
long[] nStartPos; //开始位置 9w0 ^=   
long[] nEndPos; //结束位置 n:<avl@o<  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 |{oKhC^yG  
long nFileLength; //文件长度 dr/!wr'&hS  
boolean bFirst = true; //是否第一次取文件 {5%<@<? )  
boolean bStop = false; //停止标志 X^xu$d6   
File tmpFile; //文件下载的临时信息 4El{2cfA  
DataOutputStream output; //输出到文件的输出流 cJ[n<hTv  
b<5:7C9z  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) qHHWe<}OT  
public SiteFileFetch(SiteInfoBean bean) throws IOException #4c uNX5m%  
{ 8u+ (+25  
siteInfoBean = bean; +pe_s&  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); )YnB6@=nyk  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); |}mBW@ah  
if(tmpFile.exists ()) =G=.THRUk  
{ i:[B#|%  
bFirst = false; :'!?dszS  
read_nPos(); cL1cBWd  
} 7<1Y%|x`  
else le[5a=e(  
{ t}oxHEa V  
nStartPos = new long[bean.getNSplitter()]; eq4<   
nEndPos = new long[bean.getNSplitter()]; l0@$]76cX;  
} y|lP.N/  
UoKBcarm  
dR=SW0Oa{  
,bH  
} c"QH-sE  
*i$+i  
j:sac*6m  
public void run() nK96A.B%p  
{ T Z>z5YTv  
//获得文件长度 ^d2g"L   
//分割文件 <XLATS8Y  
//实例FileSplitterFetch |Xu7cCh$me  
//启动FileSplitterFetch线程  UNhD  
//等待子线程返回 9td(MZ%i~N  
try{ KM\`,1?x92  
if(bFirst) f%|g7[  
{ ~;`i&s  
nFileLength = getFileSize(); BM3)`40[]  
if(nFileLength == -1) JTs.NY <z  
{ fi,=z  
System.err.println("File Length is not known!"); 94lmsE  
} 49kY]z|"w  
else if(nFileLength == -2) yNN2}\[.  
{ oNEU?+  
System.err.println("File is not access!"); `o*eLLk  
} A!^,QRkRN  
else % vP{C  
{ g@EKJFjl  
for(int i=0;i<nStartPos.length;i++) m[8#h(s*t  
{ bC@b9opD  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); |w>DZG!}1-  
} {< wq}~  
for(int i=0;i<nEndPos.length-1;i++) m3|,c[M1  
{ Hv IN'  
nEndPos = nStartPos[i+1]; p,1RRbyc  
} 0<Pe~i_=  
nEndPos[nEndPos.length-1] = nFileLength; @?%"nK  
} :#|77b0  
} \NSwoP  
?=T&|pp  
vu#:D1/BB  
//启动子线程 %%3ugD5i!  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Em?skUnG,  
for(int i=0;i<nStartPos.length;i++) /JfXK$`  
{ ~&q e"0  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |LjCtm)@+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ca`=dwe>  
nStartPos,nEndPos,i); kO9yei  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >l7 o/*4  
fileSplitterFetch.start(); cCj3,s/p  
} :g\qj? o  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d6n6= [*  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |0bSxPXn!  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", xGH%4J\  
nEndPos = " + nFileLength); LS_QoS  
// fileSplitterFetch[nPos.length-1].start(); ^wHO!$  
xFvSQ`sp  
"?il07+w%  
//等待子线程结束 v EX <9  
//int count = 0; VEpQT Qp  
//是否结束while循环 n/ 8fv~zU  
boolean breakWhile = false; AKWw36lm  
Gs9jX/ #  
u*U?VZ5  
while(!bStop) +HcH]D;  
{ m[7a~-3:J  
write_nPos(); E7D^6G&i  
Utility.sleep(500); R.fRQ>rI  
breakWhile = true;   C[Fh^  
zZ wD)p?_g  
U?rfE(!  
for(int i=0;i<nStartPos.length;i++) 2Hd6  
{ 8~I>t9Q+  
if(!fileSplitterFetch.bDownOver) h?O-13v   
{ %Wu8RG}  
breakWhile = false; MdKZH\z/  
break; Ay_<?F+&  
} Gm%[@7-  
} QJTC@o  
if(breakWhile) Zsuh8t   
break; 5eU/ [F9  
'nLv0.7*  
!Zwl9DX3  
//count++; jBQQ?cA  
//if(count>4) 2V0R|YUt  
// siteStop(); - Z|1@s&  
} fXqe7[  
/bb4nM_E/  
{.2C>p  
System.err.println("文件下载结束!"); :G`_IB\  
} rm cy-}e  
catch(Exception e){e.printStackTrace ();} 0O:TKgb&C.  
} )I <.DN&  
R5FjJ>JE  
mB,7YZv  
//获得文件长度 |~/{lE=I  
public long getFileSize() p\HXE4d'  
{ IW46-;l7  
int nFileLength = -1; ?L $KlF Y  
try{ MaEh8*  
URL url = new URL(siteInfoBean.getSSiteURL()); `#UTOYx4  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N,O[pTwj  
httpConnection.setRequestProperty("User-Agent","NetFox"); [J];  
AsLAm#zq  
|p+VitM7  
int responseCode=httpConnection.getResponseCode(); +X&B'  
if(responseCode>=400) Ry(!< w,  
{ $M8'm1R9  
processErrorCode(responseCode); B}jZ~/D}  
return -2; //-2 represent access is error J2R<'(  
} Ug"B/UUFd  
[DE8s[i-  
+:t1PV;l  
String sHeader; H Ow][}M_w  
;L`'xFo>>  
#8RQ7|7b|  
for(int i=1;;i++) C +IXP  
{ 'D-imLV<<  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); RDZq(rKc  
//Utility.log(in.readLine()); m ;KP  
sHeader=httpConnection.getHeaderFieldKey(i); uaGg8  
if(sHeader!=null) ^\CQWgY(  
{ (&B & V  
if(sHeader.equals("Content-Length")) |fA[s7)  
{ MHbRG_zW  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x}roPhZ  
break; E*ic9Za8`h  
} <E ^:{J95  
} x?%vqg^r  
else Gg&jb=  
break; RsY<j& f  
} AiyjrEa%  
} Q A%GK4F70  
catch(IOException e){e.printStackTrace ();} |9Y9pked8  
catch(Exception e){e.printStackTrace ();} z(]*'0)P  
%1 v)rg y  
N7E[wOP  
Utility.log(nFileLength); @M,_mX  
87HVD Di  
OUs2)H61  
return nFileLength; !At_^hSqz  
} X=JSqO6V9  
OVd"'|&6_  
=thgNMDm"  
//保存下载信息(文件指针位置) tQ)8HVKF  
private void write_nPos() w7 QIKsI0  
{ $'&5gFr9  
try{ vxwctJ&  
output = new DataOutputStream(new FileOutputStream(tmpFile)); }:BF3cH> 0  
output.writeInt(nStartPos.length); /Ly%-py-$  
for(int i=0;i<nStartPos.length;i++) ctCfLlK  
{ p7k0pSt  
// output.writeLong(nPos); Q`oi=O YB  
output.writeLong(fileSplitterFetch.nStartPos); #e#8I7P  
output.writeLong(fileSplitterFetch.nEndPos); A>PM'$"sT  
} *L^{p.K4  
output.close(); YF;8il{p  
} Ri,UHI4 W  
catch(IOException e){e.printStackTrace ();} }r i"u;.R  
catch(Exception e){e.printStackTrace ();} \Lc pl-;?  
} 5~sJ$5<,  
'UB<;6wy  
mr/^lnO  
//读取保存的下载信息(文件指针位置) 1xx-}AIH#  
private void read_nPos() jeW0;Cz J~  
{ fer'2(G?W  
try{ Zj}, VB*T  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); X{ Nif G  
int nCount = input.readInt(); A$ S9 `  
nStartPos = new long[nCount]; L*5&hPU  
nEndPos = new long[nCount]; Yd,*LYd2EL  
for(int i=0;i<nStartPos.length;i++) Y, 0O&'>  
{ B@F1!8l  
nStartPos = input.readLong(); D8h~?phK  
nEndPos = input.readLong(); r^@*Cir  
} [<%yUy  
input.close(); u54+oh|,M  
} QQ?` 1W  
catch(IOException e){e.printStackTrace ();} 8kqxr&,[  
catch(Exception e){e.printStackTrace ();} Bb1dH/8  
} C[pAa8  
>g F  
$EtZ5?qS  
private void processErrorCode(int nErrorCode) ;~@2YPj  
{ P8TiB  
System.err.println("Error Code : " + nErrorCode); 8n'C@#{WV  
} >i0FGmxH  
+/Z:L$C6  
Q0r_+0[7j  
//停止文件下载 3wr~P  
public void siteStop() 2V  
{ I*24%z9  
bStop = true; Ohjqdv@  
for(int i=0;i<nStartPos.length;i++) j$Kubg(I5  
fileSplitterFetch.splitterStop(); MVTU$ 65  
p%G\5.GcJL  
ckTnb  
} Bg#NB  
} GI~;2 `V  
//负责部分文件的抓取 S</" ^C51J  
**FileSplitterFetch.java ]=pEs6%O3  
*/ U %KoG-#  
package NetFox; XjX<?W  
!|`YNsR  
3)T5}_  
import java.io.*; ;hKn$' '  
import java.net.*; Z1>pOJm  
PvA%c<z  
x &\~4,TN  
public class FileSplitterFetch extends Thread { PL VF  
Gd'^vqo<  
Dm5UQe  
String sURL; //File URL ly{ ~X  
long nStartPos; //File Snippet Start Position + W +<~E  
long nEndPos; //File Snippet End Position (C. 1'<]  
int nThreadID; //Thread's ID Tn-H8;Hg  
boolean bDownOver = false; //Downing is over XL"e<P;t  
boolean bStop = false; //Stop identical ?$o8=h  
FileAccessI fileAccessI = null; //File Access interface Jw86P=  
Nl(Aa5:!  
21;n0E  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException xXyzzr1[  
{ }b+=,Sc"  
this.sURL = sURL; ^%_LA't'R  
this.nStartPos = nStart; on(W^ocnD  
this.nEndPos = nEnd; bhg"<I  
nThreadID = id; Oo#wPT;1^(  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #7g~U m%p  
} u{\`*dNx  
1&m08dZm5  
iPs()IN.O  
public void run() 5v?6J#]2  
{ _o`'b80;  
while(nStartPos < nEndPos && !bStop) 1~_]"Y'  
{ PPmZ[N9(;  
K7y}R%Q F  
]r#tJ T`M  
try{ #_H=pNWe  
URL url = new URL(sURL); nhy3E  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H{+U; 6b  
httpConnection.setRequestProperty("User-Agent","NetFox"); 2/h Mx-  
String sProperty = "bytes="+nStartPos+"-"; "cti(0F-d  
httpConnection.setRequestProperty("RANGE",sProperty); TX 12$p\  
Utility.log(sProperty); 6bU/IVP  
*Fq Nzly  
yJgnw6>r2  
InputStream input = httpConnection.getInputStream(); "3!4 hiU9  
//logResponseHead(httpConnection); mT~:k}u~W  
iedoL0#  
D@0eYX4s  
byte[] b = new byte[1024]; JM M\  
int nRead; j7i[z>:Y  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &18} u~M  
{ W<58TCd  
nStartPos += fileAccessI.write(b,0,nRead); NW~n+uk5v  
//if(nThreadID == 1) dLo%+V#/A  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6)H70VPJ  
} T9(~^}_+9  
2Ejs{KUj  
B\4SB  
Utility.log("Thread " + nThreadID + " is over!"); VGe/;&1h  
bDownOver = true; |&C.P?q  
//nPos = fileAccessI.write (b,0,nRead); $<T)_g  
}  ) .#,1  
catch(Exception e){e.printStackTrace ();} (I\aGGW  
} 8mMrGf[Q\  
} H,?AaM[V  
3J@# V '  
IoA"e@~t  
//打印回应的头信息 ) I@gy  
public void logResponseHead(HttpURLConnection con) ?SS?I  
{ y/Nvts2!C  
for(int i=1;;i++) 4cs`R+]o  
{ ;B tRDKn  
String header=con.getHeaderFieldKey(i); }G-qOt  
if(header!=null) 9}5Q5OZ  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vL-%"*>v  
Utility.log(header+" : "+con.getHeaderField(header)); jd~r~.y  
else _hXadLt  
break; \24neD4cM@  
} *S ;v406  
} ~C[R%%Gu  
qA*QFQ'-  
Kw'A%7^e  
public void splitterStop() RMsr7M4<91  
{ Oa*/jZjr  
bStop = true; KaO8rwzDN  
} r$*k-c9Bf  
F[Peil+|`  
B9+oI c O  
} P 0,]Ud  
<m9IZI Y<  
PN<Y&/fB  
/* jb77uH_  
**FileAccess.java o.sa ?*  
*//文件访问(定位,写) 3}XUYF;  
package NetFox; V_0e/7}Ya  
import java.io.*; II),m8G  
?2Bp^3ytJ  
3~M8.{ U#V  
public class FileAccessI implements Serializable{ $yOfqr  
Kx#G_N@  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |f`!{=?  
RandomAccessFile oSavedFile; I_N"mnn@Nr  
long nPos; pcL02W|J  
G!%1<SLi.  
lQ)ZsFs=  
public FileAccessI() throws IOException -O-_F6p'D  
{ utRvE(IbmV  
this("",0); E-&=I> B5  
} {iHC;a5gb$  
S[*e K Z  
.lRO; D  
public FileAccessI(String sName,long nPos) throws IOException Rqu;;VI[  
{ =@B9I<GKf  
oSavedFile = new RandomAccessFile(sName,"rw"); ()XL}~I{!A  
this.nPos = nPos; !+CRS9\D   
oSavedFile.seek(nPos); Qx$Yj  
} |9 }G  
Z@j0J[s  
44wY5nYNt  
public synchronized int write(byte[] b,int nStart,int nLen) CJ KFNa  
{ 6ffrV  
int n = -1; 6rdm=8WFA  
try{ }LQ&AIRN  
oSavedFile.write(b,nStart,nLen); "jb?P$  
n = nLen; \'j%q\Bl;  
} 5AQ $xm4  
catch(IOException e) k g+"Ta[9  
{ >m%\SuXq  
e.printStackTrace (); H6*F?a`)I  
} ;J2=6np  
}1epn#O_4  
-`#LrO;n  
return n; nqy\xK#.^  
} 3 u-j`7  
5(TI2,4  
_?`3zm4  
} vhdT"7`U  
8h-6;x^^  
BDc*N]m}B1  
/* u'LA%l-  
**SiteInfoBean.java Pp #!yMxBr  
*/ CEZ*a 0}=  
package NetFox; aRg- rz  
 8tLkJOu  
!!dNp5h`  
public class SiteInfoBean { LV'v7 2yUH  
Ij/c@#q.  
v5 $"v?PT  
private String sSiteURL; //Site's URL Uu8Z2M  
private String sFilePath; //Saved File's Path q4lL7@_  
private String sFileName; //Saved File's Name jb fMTb4  
private int nSplitter; //Count of Splited Downloading File :^! wQ""  
F5{~2~Cw(  
8`9!ocrM  
public SiteInfoBean() 8[ :FU  
{//nSplitter的缺省值为5 A+NLo[swwu  
//default value of nSplitter is 5 D",ZrwyJ  
this("","","",5); )7[>/2aGd  
} ka*VQXk*  
'2v,!G]^  
; #e-pkV  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c :hOQZ  
{ !dSY?1>U<  
sSiteURL= sURL; f4]nz:2  
sFilePath = sPath; ^MDBJ0 I.  
sFileName = sName; ) Q]kUG#`  
this.nSplitter = nSpiltter; Pgs4/  
v!K %\h2A  
!f]F'h8  
} |OuZaCJG  
qvhTc6oH  
Kl\A&O*{  
public String getSSiteURL() ub./U@ 1  
{ cM.q^{d`  
return sSiteURL; ~@MIG  
} [Gysx  
=-`X61];M  
`N ;!=7y7Y  
public void setSSiteURL(String value) p*n$iroy_{  
{ ,$7LMTVDrE  
sSiteURL = value; e2k!5O S  
} {_KuztJGA  
3-~_F*%ST  
$Ob]JAf}  
public String getSFilePath() <fWho%eOK  
{ /Y%) Y  
return sFilePath; I?Eh 0fI  
} 5|wQeosXxI  
XOVZ'V  
J(g!>Sp!p  
public void setSFilePath(String value) u*}6)=+:  
{ Xq+7l5LP  
sFilePath = value; Z9 }qds6 y  
} _N0x&9S$  
q$~S?X5\  
4- N>#  
public String getSFileName() I)O%D3wfMW  
{ jZe]zdml  
return sFileName; 1K4LEg a`  
} QWxCNt:^?  
E+UOuf*(  
k;l^wM  
public void setSFileName(String value) 6D _4o&N  
{ <o^mQq&  
sFileName = value; OA&NWAm4  
} ?^5W.`Y2i  
ps_CQh0  
ib*$3Fn~  
public int getNSplitter() I&1h/  
{ R qOEQ*k  
return nSplitter; 64o`7  
} Td X6<fVV  
>LwAG:Ud  
l?Bv9k.^?  
public void setNSplitter(int nCount) "JbFbcj  
{ :G$NQ* (z  
nSplitter = nCount; Uiv;0Tovl  
} g}L2\i688  
} VOp8 ,!  
6@; w%Ea  
73Tg{~  
/* [&3G `8hY  
**Utility.java f+1)Ju~  
*/ #^%Rk'W  
package NetFox; /,$6`V  
daY^{u3  
>{ne!  
public class Utility { g6;O)b  
pG:FDlR~  
H /*^$>0Uo  
public Utility() ?gH[tN:=  
{ mzfj!0zR*  
Q3_ia 5 `O  
,r:. 3.  
} ([`-*Hy  
`"Tx%>E(U  
//线程睡眠 2p(K0PtX  
public static void sleep(int nSecond) O BF5Tl4  
{ T->O5t c  
try{ Y&]pC  
Thread.sleep(nSecond); 3QM.X^ANH  
} |P>> ^,iUn  
catch(Exception e) 3[-L'!pOX3  
{ ?v8B;="#w  
e.printStackTrace (); >=r094<  
} aG`G$3_wx  
} ~Se/uL;*  
FwmE1,  
//日志 ].7)^  
public static void log(String sMsg) =/V r,y$  
{ Bn-%).-ED  
System.err.println(sMsg); #0hX)7(j  
} *.ZV.(  
Xp4pN{he  
+w%MwPC7`  
public static void log(int sMsg) yngSD`b_P  
{ rM_8piD  
System.err.println(sMsg); D9 ,~Fc  
} d=Q0 /sI&  
} [;h@ q}  
HVh+Z k  
mY |$=n5X  
/* zA\DI]:+  
**TestMethod.java %(,JBa:G  
*/ <?2[]h:wp  
package NetFox; s{Ryh.IyI  
0E o*C9FP~  
57%:0loW  
public class TestMethod { *-Z JF6  
pc:~_6S  
haqL DVrf  
public TestMethod() cuW$%$ F  
{ ///xx/weblogic60b2_win.exe $*`fn{2  
try{ `?2S4lN/  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W 29@`93  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;_1D-Mf  
SiteFileFetch fileFetch = new SiteFileFetch(bean); :&9#p% /  
fileFetch.start(); N=)N   
} y*2:(nI  
catch(Exception e){e.printStackTrace ();} KR?-<  
(VU: &.  
;~tKNytD`B  
} dHg[0Br)r  
SI4M<'fK  
o%RyE]pw,  
public static void main(String[] args) 7K%Ac  
{ B ,e3r  
new TestMethod(); pR; AqDQ  
} s@K|zOx  
} ko=vK%E[  
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:
10+5=?,请输入中文答案:十五