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
  • 12140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
/* x zu)``?  
**SiteFileFetch.java wUj[c7Y%  
*/ Ac}+U q  
package NetFox; A#$oY{"2Y  
import java.io.*; _0ki19rs  
import java.net.*; XQ]noaU  
hdt;_qa   
w%R(*,r6  
public class SiteFileFetch extends Thread { &?flH;  
t?f2*N :  
ste0:.*qb  
SiteInfoBean siteInfoBean = null; //文件信息Bean ]:jP*0bLx  
long[] nStartPos; //开始位置 ^N#B( F  
long[] nEndPos; //结束位置  |`[0U  
FileSplitterFetch[] fileSplitterFetch; //子线程对象  PNY"Lqj  
long nFileLength; //文件长度 <5(P4cm9  
boolean bFirst = true; //是否第一次取文件 X c~yr\%]  
boolean bStop = false; //停止标志 #&<>|m  
File tmpFile; //文件下载的临时信息 N Q~keN  
DataOutputStream output; //输出到文件的输出流 <]<P<  
V .+ mK|)  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Q`- JRY-  
public SiteFileFetch(SiteInfoBean bean) throws IOException RQhS]y@e  
{ DCr&%)Ll  
siteInfoBean = bean; @=JOAo  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); a!rU+hiC  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ?e( y/  
if(tmpFile.exists ()) z6 T3vw  
{ :_9MS0  
bFirst = false; B!{vSBq  
read_nPos(); r ,I';vm<`  
} [Z~h!}  
else DmzK* O{  
{ qj|P0N{7  
nStartPos = new long[bean.getNSplitter()]; Bv-|#sdxm  
nEndPos = new long[bean.getNSplitter()]; j#4 Iu&YJ  
} w]<V~X  
u~b;m  
^#-d^ )f;  
ws}cMX]*  
} /bm2v;  
v *'anw&Z  
6!F@?3qCyg  
public void run() o>4mkh[3  
{ @ ;T|`Y=7  
//获得文件长度 Yf1&"WW4  
//分割文件 c,@&Z#IZ`  
//实例FileSplitterFetch 7Yv1et |  
//启动FileSplitterFetch线程 8w4-Ud*$i  
//等待子线程返回 ]'IZbx:  
try{ HrOq>CSR  
if(bFirst) o,qq*}=  
{ BQWhTS7  
nFileLength = getFileSize(); {L6@d1u  
if(nFileLength == -1) rF@njw@  
{ +lYo5\1=  
System.err.println("File Length is not known!"); |:7 ^  
} >T{Gl/? p  
else if(nFileLength == -2) Fw{:fFZC[  
{ )NF5,eD  
System.err.println("File is not access!"); L i g7Ac,  
} g2 RrBK,  
else 1s-dqHz"s  
{ "FD`1  
for(int i=0;i<nStartPos.length;i++) `GDWy^-Q+!  
{ hw 5NHZ I'  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 5S9i>B  
} jm ORKX+)  
for(int i=0;i<nEndPos.length-1;i++) I3I1<}>]Z  
{ '@0Z#A  
nEndPos = nStartPos[i+1]; 1j_gQ,'20  
} *VX"_C0Jy=  
nEndPos[nEndPos.length-1] = nFileLength; !k3 eUBF  
} C(%b!Q,2  
} "1P[D'HV4|  
ayGcc`  
ohJo1}{  
//启动子线程 y:HH@aa)  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bmzY^ %a  
for(int i=0;i<nStartPos.length;i++) +,Ud 3iS  
{ L*6R5i>  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WqO4_;X6/  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4j1$1C{  
nStartPos,nEndPos,i); oBS m>V  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Hk8lHja+\  
fileSplitterFetch.start(); ^j!2I&h1  
} Z g.La<#  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), | LX Vf  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 41v#|%\w  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b!<\#[ A4  
nEndPos = " + nFileLength); *t{^P*pc  
// fileSplitterFetch[nPos.length-1].start(); O#@G .~n?  
diWi0@  
[.Rdq]w6  
//等待子线程结束 $L4h'(s  
//int count = 0; "h5.^5E6  
//是否结束while循环 ^~1Z"kAnT  
boolean breakWhile = false; <y=+Gh  
H?_wsh4J  
4aiI&,  
while(!bStop) 6b1AIs8  
{ |jB/d@RE  
write_nPos(); #F=!g?  
Utility.sleep(500); *.6m,QqJ(  
breakWhile = true; MW2{w<-]7  
hLr\;Swyp  
nN2huNTf:  
for(int i=0;i<nStartPos.length;i++) ES\=MO5a7  
{ }60/5HNr  
if(!fileSplitterFetch.bDownOver) g/ 4ipcG;N  
{ gtnu/ Q  
breakWhile = false; 0V ZC7@  
break; 7NRm\%^q  
} *zwo="WA\t  
} 7Bym?  
if(breakWhile) v~A*?WU;n  
break; [pC2#_}  
X4<Y5?&0  
d2?#&d'aq  
//count++; l<;~sag  
//if(count>4) qfX26<q  
// siteStop(); RF= $SMTk  
} '5(T0Ws/w  
?vfZ>7Q  
-zzoz x]S=  
System.err.println("文件下载结束!"); 81H9d6hqcD  
} _C)\X(;  
catch(Exception e){e.printStackTrace ();} H*P[tyz$  
} 1ozb tn  
v_Hy:O}R  
*L~?.9R  
//获得文件长度 "d`u#YmR  
public long getFileSize() &xpvHKJl  
{ c^<~Y$i  
int nFileLength = -1; uvAJJIae'  
try{ 8F&Y;  
URL url = new URL(siteInfoBean.getSSiteURL()); Iw^Q>MrT  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pqTaN=R8  
httpConnection.setRequestProperty("User-Agent","NetFox"); %=Y=]g2  
tAPf#7{|   
dvM%" k  
int responseCode=httpConnection.getResponseCode(); w"37sv  
if(responseCode>=400) m Ga:~x  
{ 6Jq3l_  
processErrorCode(responseCode); H:P7G_!\  
return -2; //-2 represent access is error Dr76+9'i  
} PuhvJHT  
7X)4ec9H\  
;XQ27,K&  
String sHeader; 5,4m_fBoW  
sm;kg=  
=\ k:]  
for(int i=1;;i++) =kf"%vFV  
{ {5fL!`6w  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); do*aE  
//Utility.log(in.readLine()); nEPTTp+B  
sHeader=httpConnection.getHeaderFieldKey(i); ` Z/ MQ  
if(sHeader!=null) Abi(1nXdQ  
{ f7|Tp m  
if(sHeader.equals("Content-Length")) ^KnK \  
{ 1{wbC)  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J7qTE8W=  
break; +,]VXH<y  
} kv6nVlI)B  
} 0m=57c$O  
else =6+99<G|%M  
break; B,&QI&k`~  
} ($>m]|  
} awI{%u_(nA  
catch(IOException e){e.printStackTrace ();} }'faf{W  
catch(Exception e){e.printStackTrace ();} I!Z"X&  
m=+x9gL2  
o(H.1ESk  
Utility.log(nFileLength); $PI9vyS  
H cyoNY  
?3 k_YN"  
return nFileLength; 89;@#9  
} 9zS   
.c:h!-D;  
3Pllxq<n  
//保存下载信息(文件指针位置) .Zj`_5C  
private void write_nPos() D,R',(3  
{ kY!zBk  
try{ Aq*?Q/pV  
output = new DataOutputStream(new FileOutputStream(tmpFile)); > <Zu+HX  
output.writeInt(nStartPos.length); T1*.3_wtP  
for(int i=0;i<nStartPos.length;i++) h6OQeZ.  
{ "bDj 00nwh  
// output.writeLong(nPos); AWYlhH4c?t  
output.writeLong(fileSplitterFetch.nStartPos); %Zbm%YaW5  
output.writeLong(fileSplitterFetch.nEndPos); q\x.e.@  
} @4D{lb"{  
output.close(); zL9~gJ  
} 7s#8-i  
catch(IOException e){e.printStackTrace ();} R ZQH#+*t}  
catch(Exception e){e.printStackTrace ();} ZJQFn  
} R y#C#0  
]X77?Zz9  
Um 6}h@>  
//读取保存的下载信息(文件指针位置) <Q/)SN6_E  
private void read_nPos() VXWV Pj#  
{ {_\cd.AuT  
try{ pCrm `hy(  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5cinI^x)f  
int nCount = input.readInt(); N`,\1hHMT  
nStartPos = new long[nCount]; cS7\,/4S  
nEndPos = new long[nCount]; `D |/g;  
for(int i=0;i<nStartPos.length;i++) %" 7UYLX  
{ ^@O 7d1&y  
nStartPos = input.readLong(); R"V90bCf  
nEndPos = input.readLong();  MiIxj%,(  
} qar{*>LCG  
input.close(); l^nvwm`f#:  
} D@gC(&U/6  
catch(IOException e){e.printStackTrace ();} 05T?c{ ;  
catch(Exception e){e.printStackTrace ();} T+&fUhSy  
} XLCqB|8`V  
R|M]mwa^w  
Y;_F,4H  
private void processErrorCode(int nErrorCode) <tF q^qB  
{ y zp#  
System.err.println("Error Code : " + nErrorCode); qe{;EH*  
} 9QXsbd6  
#jg-q|nd  
GHd1?$  
//停止文件下载 v0oVbHO5<  
public void siteStop() ]zaTX?F:  
{ 7;AK=;  
bStop = true; &d2L9kTk  
for(int i=0;i<nStartPos.length;i++) 1L4-;HYJm  
fileSplitterFetch.splitterStop(); q%])dZ!lE  
U|tacO5w`  
SDO:Gma  
} G&^8)S@1  
} TS9<uRO0  
//负责部分文件的抓取 3= sBe HL  
**FileSplitterFetch.java g^+p7G  
*/ 9X 4[Zk  
package NetFox; h>D;QY  
}k-8PG =  
:G@z?ZJ[  
import java.io.*; 8Lx/ZGy  
import java.net.*; L7buY(F(  
?# FYF\P  
lr~ |=}^  
public class FileSplitterFetch extends Thread { 1m"WrTen  
7:?\1 a  
~:7y!=8#  
String sURL; //File URL !;,\HvEZYw  
long nStartPos; //File Snippet Start Position x;yvv3-$  
long nEndPos; //File Snippet End Position I*.nwV<  
int nThreadID; //Thread's ID 5s3QN{h8  
boolean bDownOver = false; //Downing is over {Z8GG  
boolean bStop = false; //Stop identical 56<UxIa~  
FileAccessI fileAccessI = null; //File Access interface |Qcz5M90e  
;X<Ez5v3  
 Jk(V ]  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #;ObugY,  
{ @,.D]43  
this.sURL = sURL; V 9$T=[  
this.nStartPos = nStart; 0)d='3S  
this.nEndPos = nEnd; W..*!UGl  
nThreadID = id; jdJTOT  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 E Ou[X'gLr  
} ,M{G X  
H%Gz"  
!xck ~EAS  
public void run() %p  
{ o FP8s[B  
while(nStartPos < nEndPos && !bStop) ^zV_ vB)n  
{ # tu>h  
a_P|KRl  
XjL3Ar*  
try{ Fdhgm{Y2s  
URL url = new URL(sURL); z7IJSj1gQI  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \O "`o4  
httpConnection.setRequestProperty("User-Agent","NetFox"); 1xS+r)_n@  
String sProperty = "bytes="+nStartPos+"-"; WC<[<uI*  
httpConnection.setRequestProperty("RANGE",sProperty); /J-'[Mc'D[  
Utility.log(sProperty); I9G^T' W  
nQOdM#dP  
1Mp-)-e  
InputStream input = httpConnection.getInputStream(); ni{'V4A  
//logResponseHead(httpConnection); ~|S0E:*.  
yR|2><A  
Lq>lj`>  
byte[] b = new byte[1024]; ;dUKFdKH}  
int nRead; $Okmurnn  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) GgY8\>u  
{ %:`v.AG  
nStartPos += fileAccessI.write(b,0,nRead); 1Z c=QJw@  
//if(nThreadID == 1) d*{Cv2A.  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZcjLv  
} WcqR; Nm  
+^(_S9CO  
N,qo/At}R[  
Utility.log("Thread " + nThreadID + " is over!"); FCNYfjB%  
bDownOver = true; 2LUsqL\m}.  
//nPos = fileAccessI.write (b,0,nRead); 7d>w]R,Z  
} G?$o+Y'F  
catch(Exception e){e.printStackTrace ();} Z(|$[GZP[  
} <}[ !k<  
} I ==)a6^  
f> Jj5he/  
8d5#vm  
//打印回应的头信息 + GQ{{B  
public void logResponseHead(HttpURLConnection con) \0 h>!u  
{ -&7? !<f  
for(int i=1;;i++) ^AU-hVj  
{ W8^A{l4  
String header=con.getHeaderFieldKey(i); >xo<i8<Miv  
if(header!=null) n~yHt/T  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3@x[M?$  
Utility.log(header+" : "+con.getHeaderField(header)); El9T>!Z  
else ?1\I/ 'E9  
break; n+sv2Wv:  
} q-Z<.GTq  
} p35)K5V  
aPxSC>p  
,H6P%  
public void splitterStop() j;}-x1R  
{ BN]o!Y  
bStop = true; 0-uj0"r`  
} Xk|a%%O*H  
9U<WR*H  
YG0/e#5  
} ktqFgU#rT  
W gyRK2#!  
Pq+|*Y<|&  
/* [/hoNCH!  
**FileAccess.java #0r^<Yn  
*//文件访问(定位,写) A94:(z;{  
package NetFox; hb*Y-$Zp  
import java.io.*; 83vZRQw  
moFrNcso  
-<x%  
public class FileAccessI implements Serializable{ aK6dy\  
e:-pqZT`  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 aoW2c1`?Z  
RandomAccessFile oSavedFile; r+%3Y:dZE  
long nPos; Y{j~;G@Wl  
QyTN  V  
4Wz1O$*  
public FileAccessI() throws IOException ?pJ2"/K   
{ *.w6 =}  
this("",0); Oi|cTZ@A-  
} _s#J\!F  
 Yf[Cmn  
V8F! o  
public FileAccessI(String sName,long nPos) throws IOException <k1muSe  
{ :fRta[  
oSavedFile = new RandomAccessFile(sName,"rw"); MbYgGE,LA  
this.nPos = nPos; BIMX2.S1o  
oSavedFile.seek(nPos); 1H">Rb30@  
} )2EvZn  
<^;~8:0]  
qYe`</  
public synchronized int write(byte[] b,int nStart,int nLen) @+~URIG)  
{ _0naqa!JyH  
int n = -1; cyd_xB5K  
try{ Fi+ DG?zu  
oSavedFile.write(b,nStart,nLen); +-t&li%F  
n = nLen;  -+qg  
} 2@_3V_  
catch(IOException e) K;THYMp/[  
{ ec^{ez@`  
e.printStackTrace (); gYh o$E  
} hUi5~;Q5Fi  
K ..Pn 17t  
Pt-mLINvG  
return n; 8M3DG=D  
} 56c3tgVF  
, =*^XlO=c  
p `oB._ R  
} }3 ~*/30V  
;gaTSYVe  
fUq}dAs*K  
/* U\{I09@E 0  
**SiteInfoBean.java 7]5+%[Dg!  
*/ nF3Sfw,  
package NetFox; kMzDmgoxNg  
 5B1,,8P  
/HqD4GDoug  
public class SiteInfoBean { =RWY0|f  
kot KKs   
~h+B&F+5  
private String sSiteURL; //Site's URL | Cfo(]>G  
private String sFilePath; //Saved File's Path Ak`?,*L M  
private String sFileName; //Saved File's Name G'HLnx}Yi  
private int nSplitter; //Count of Splited Downloading File (7~vOWs:[  
ex|)3|J  
Uq%|v  
public SiteInfoBean() sSiZG  
{//nSplitter的缺省值为5 E>QEI;  
//default value of nSplitter is 5 )OlYz!#?  
this("","","",5); ;%>X+/.y0  
} Jx&+e,OST  
nu|?F\o!  
D* HK[_5  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) da8 R.1o  
{ (Zy=e?E,  
sSiteURL= sURL; jNIz:_c-~  
sFilePath = sPath; HqOnZ>D  
sFileName = sName; !C.{nOfyv  
this.nSplitter = nSpiltter; ov>`MCS,v  
FQJFq6l  
3fop.%(  
} 9I|Q`j?p`  
R,zp&L  
4x/u$Ixzh=  
public String getSSiteURL() "bjbJC&T  
{ mL, {ZL ^  
return sSiteURL; \>eFs} Y/  
} B7'2@+(  
t6+>Zr  
C|ou7g4'p  
public void setSSiteURL(String value) S7hfwu&7F  
{ 1T3YFt@&I  
sSiteURL = value; Y7yzM1?t  
} %bnjK#o"Q  
69C ss'  
<DdzDbgax  
public String getSFilePath() klj.\wg/p{  
{ Q[Tbdc%1EG  
return sFilePath; o\y qf:V8  
} (b1rd  
N<lf,zGw  
%{P." ki  
public void setSFilePath(String value) D-5~CK4`  
{ (WS<6j[q  
sFilePath = value; n<sA?T  
} ~_SVQ7P  
&sPu 3.p  
yz=6 V%  
public String getSFileName() Z@:R'u2Lk  
{ n %P,"V  
return sFileName; 'P)[=+O?t  
} %6<2~  
X1h*.reFAL  
3qH`zYgh  
public void setSFileName(String value) DWJkN4}o  
{ 4=n%<U`Z/  
sFileName = value; cE]#23  
} @sb00ad2q  
b(gcnSzM2  
9]/j u  
public int getNSplitter() 7wc{.~+  
{ s((_^yf  
return nSplitter; FUTDR-q O  
} Y~bGgd]T  
! J@pox-t  
gbRdng7(}  
public void setNSplitter(int nCount) -[`FNTTV C  
{ c )o[3o7  
nSplitter = nCount; 5Bc)QKh`l|  
} }GTy{Y*&  
} pNzGpCk  
4.mbW  
<ByDT$E_  
/* IsCJdgG  
**Utility.java pBu~($%d  
*/ !bCLi>8  
package NetFox; %z0@4G q  
!P26$US%P  
U!x\oLP  
public class Utility { Qmh*Gh? v  
KhV; />(  
B1Iq:5nmoS  
public Utility() *ha9Vq@X  
{ "]`QQT-{0  
ZvO:!u0+"  
G1'w50Yu  
} )FqE8oN-  
<cz~q=%v2&  
//线程睡眠 v+=_  
public static void sleep(int nSecond) 7iKbd  
{ Swua dN  
try{ ~ +$l9~`{  
Thread.sleep(nSecond); ':w6 {b  
}  OkO"t  
catch(Exception e) 9aC>gye!  
{ `"CF/X^  
e.printStackTrace (); [P{Xg:0  
} `czXjZE  
} q+o(`N'~G  
8YN+ \  
//日志 tZXtt=M w  
public static void log(String sMsg) I/)dXk~  
{ ]yVB66l  
System.err.println(sMsg); X>|.BvY|  
} hoeTJ/;dm  
<$njU=YE&  
>8tE`2[i*  
public static void log(int sMsg) W#y)ukRv  
{ {YbqB6zaM  
System.err.println(sMsg); Vq'&t<K#  
} ,_lwT}*w  
} :({lXGc}4?  
4'rk3nT8  
V`WfJ>{;Z  
/* "3j0)  
**TestMethod.java c@q>5fR/c  
*/ .(1$Q6yG  
package NetFox; JrL/LGY  
uV 6f~cQ  
WD?V1:>+  
public class TestMethod { nQ(#'9  
w pCS]2  
_1R`xbV  
public TestMethod() *j*jA/  
{ ///xx/weblogic60b2_win.exe @e0 Q+t  
try{ Zz3#Kt5t3  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); n'h )(^  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6|dUz*Pr|\  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7e=a D~f  
fileFetch.start(); [ $"iO#oO  
} eO9nn9lql  
catch(Exception e){e.printStackTrace ();} gaCGU<L  
Z?Q2ed*j  
.N+xpxdG,  
} PvB?57wkF  
7kwG_0QO  
*/+s^{W7  
public static void main(String[] args) =}"hC`3e  
{ V[bc-m  
new TestMethod(); BxT~1SBFq  
} Sd\@Q% }o\  
} p.\KmEx  
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 或 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