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
  • 11042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
/* c3 &m9zC  
**SiteFileFetch.java efz&@|KR  
*/ $WW)bP d4^  
package NetFox; D';eTy Y  
import java.io.*; 'YSuQP>  
import java.net.*; ;,O fJ'q^  
;\%sEcpT  
xeTgV&$@  
public class SiteFileFetch extends Thread { l|/:Ot  
Z"I/ NGiU  
eUO9 a~<  
SiteInfoBean siteInfoBean = null; //文件信息Bean Z%gx%$  
long[] nStartPos; //开始位置 >P. 'CU  
long[] nEndPos; //结束位置 f0Hq8qAF;^  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 y:}sD_m0W  
long nFileLength; //文件长度 99 wc  
boolean bFirst = true; //是否第一次取文件 sNU}n<J-  
boolean bStop = false; //停止标志 mE#nU(+Ta  
File tmpFile; //文件下载的临时信息 #< CIFVH  
DataOutputStream output; //输出到文件的输出流 BC\S/5~k  
l!IKUzt)7  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) \.s`n2.w  
public SiteFileFetch(SiteInfoBean bean) throws IOException ,R wfp=*E  
{ gmSQcN)  
siteInfoBean = bean; ,7d|O}B  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); o`r(`6@  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); YT yX`Y#  
if(tmpFile.exists ()) v vE\  
{ `3iQZu i  
bFirst = false; ?n'O Fpd  
read_nPos(); %kU'hzLg  
} q9}m!*8e  
else '=cKU0 G#  
{ `EMi0hm&H  
nStartPos = new long[bean.getNSplitter()]; msk/p>{O  
nEndPos = new long[bean.getNSplitter()]; $->d!  
} keqcV23k  
>[*4Tjg  
%"Db?  
2'{}<9  
} </E>tMW  
@%W]".*'}  
G{c#\?12C  
public void run() ;rBp1[qVe  
{ 5JFV%odo  
//获得文件长度 ]HvZ$  
//分割文件 [6g O  
//实例FileSplitterFetch h{]#ag5`  
//启动FileSplitterFetch线程 w+f=RHX"{  
//等待子线程返回 O]nT>;PXX  
try{ RIhOR8 )  
if(bFirst) jQtSwVDr  
{ :%tuNJjj  
nFileLength = getFileSize(); d\]O'U)s  
if(nFileLength == -1) Bh`IXu  
{ v:d9o.h  
System.err.println("File Length is not known!"); Q~ 0Dfo w?  
} Gq]d:-7l  
else if(nFileLength == -2) ]h~o],:  
{ D[>W{g $  
System.err.println("File is not access!"); g#W_S?  
} M#0 @X  
else 7U:=~7GH  
{ W^xZ+]  
for(int i=0;i<nStartPos.length;i++) |Cf mcz(56  
{ LV.&>@*  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); [b`6v`x  
} ')nnWlK  
for(int i=0;i<nEndPos.length-1;i++) %2yAvGa1  
{ elbG\qXBp  
nEndPos = nStartPos[i+1]; .C5@QKU  
} T"W9YpZ  
nEndPos[nEndPos.length-1] = nFileLength; %ejeyc  
} iVeQ]k(u  
} ="B n=>  
.5g}rxO8  
oCJbkt=  
//启动子线程 !Z/$}xxj  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H`D f  
for(int i=0;i<nStartPos.length;i++) F!~l MpuE  
{ )vHi|~(   
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V} bM!5 H  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), R=35 7^[R  
nStartPos,nEndPos,i); ){tPP$-i=  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |s`Kd-'|q  
fileSplitterFetch.start(); ?L`ZKRD  
} K^ 6+Ily  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v>at/ef  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .;slrg(5F  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ed=}PrE  
nEndPos = " + nFileLength); & s-VSu7  
// fileSplitterFetch[nPos.length-1].start(); $,P\)</ VR  
=>YvA>izE  
!`C%Fkq  
//等待子线程结束 dzxI QlP  
//int count = 0; "/y|VTV"  
//是否结束while循环 AM?Ec1S #a  
boolean breakWhile = false; 5bBCpNa  
DR{] sG  
ji##$xC  
while(!bStop) A`C-sD >  
{ _m7c o :  
write_nPos(); {]M>Y%j48  
Utility.sleep(500); )G4rJ~#@  
breakWhile = true; ;KS`,<^-  
ZeTL$E[E}  
FF@`+T  
for(int i=0;i<nStartPos.length;i++) irmwc'n]  
{ cUC17z2D  
if(!fileSplitterFetch.bDownOver) ._ih$=   
{ ^^ j/  
breakWhile = false; _3U|2(E  
break; l4Y1(  
} >p |yf. G  
} xSOoIsL[  
if(breakWhile) MHNe>C-!q  
break; gA:[3J,[;  
CK Mv7  
iUCwKpb9  
//count++; U IQ 6SvM  
//if(count>4) e/P4mc)  
// siteStop(); CKN8z  
} 2*YP"Ryh  
\6LcVik  
{9'hOi50  
System.err.println("文件下载结束!"); [,nfAY  
} J=V yyUB  
catch(Exception e){e.printStackTrace ();} kdd7X bw-  
} kDg{ >mf  
wXcMt>3  
(NM6micc  
//获得文件长度 <>&89E%j'  
public long getFileSize() dh?S[|='  
{ XqX I(q^  
int nFileLength = -1; s+N^PX3  
try{ ,0.|P`|w  
URL url = new URL(siteInfoBean.getSSiteURL()); &*ZC0V3  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ' XEK&Yi1  
httpConnection.setRequestProperty("User-Agent","NetFox"); #!Ze\fOC  
?KCxrzf  
Z]p8IH%~92  
int responseCode=httpConnection.getResponseCode(); 2| $k`I,  
if(responseCode>=400) h^v9|~ZJ'7  
{ hOl=W |)v  
processErrorCode(responseCode); `:R-[>5P8  
return -2; //-2 represent access is error F\Y,JUn[G  
} |zb`&tv}  
oX#9RW/ >I  
-P*xyI  
String sHeader; -D;lS 6  
BM.-X7)  
Q+HZ?V(  
for(int i=1;;i++) @F~0p5I  
{ pB[%:w/@l:  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .oEFX8  
//Utility.log(in.readLine()); EuLXtq  
sHeader=httpConnection.getHeaderFieldKey(i); A mvw`u>  
if(sHeader!=null) 0|GpZuGO9  
{ a2[ 8wv1  
if(sHeader.equals("Content-Length")) $xQ"PJ2  
{ yX3PUO9  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); phe"JNML  
break; IF& PGo  
} G1p43  
} F"Uh/EO<  
else U~Xf=f_Q$  
break; !>q?dhw@  
} )< l\jfx e  
} df!+T0  
catch(IOException e){e.printStackTrace ();} FSFFk~  
catch(Exception e){e.printStackTrace ();} N JXa_&_  
jjYM3LQcdP  
_qEWu Do  
Utility.log(nFileLength); 5a8JVDLX^  
'+tKvTU;  
HqB|SWyK  
return nFileLength; VVgsLQd  
} Ko@zk<~"[  
Jm%mm SYK  
*ZX!EjICk  
//保存下载信息(文件指针位置) OA!R5sOz"  
private void write_nPos() vP-3j  
{ VPdwSW[eM  
try{ @pTD{OW?  
output = new DataOutputStream(new FileOutputStream(tmpFile)); SHytyd  
output.writeInt(nStartPos.length); Q +R3H,  
for(int i=0;i<nStartPos.length;i++) U2VV[e)Z!  
{ B<(Pd  
// output.writeLong(nPos); OuMco+C  
output.writeLong(fileSplitterFetch.nStartPos); >7"$}5d  
output.writeLong(fileSplitterFetch.nEndPos); "^Y6ctw  
} }7-7t{G  
output.close(); `Fz\wPd  
} &3jBE --  
catch(IOException e){e.printStackTrace ();} Lf[G>0t&n  
catch(Exception e){e.printStackTrace ();} !-F^VGD(8  
} 7 kEx48  
Oi6f8*,  
P= &'wblm?  
//读取保存的下载信息(文件指针位置) : x>I- 3G  
private void read_nPos() P"oYC$  
{ f<'n5}{RO0  
try{ a$~IQ2$|6  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); E(7@'d{o  
int nCount = input.readInt(); B:B8"ODV  
nStartPos = new long[nCount]; a|8| @,  
nEndPos = new long[nCount]; ,LoMt ]H  
for(int i=0;i<nStartPos.length;i++) &b 5T&-C<  
{ vYYS .ve  
nStartPos = input.readLong(); dK[*  
nEndPos = input.readLong(); _{[k[]  
} MV% :ES?  
input.close(); M ' a&  
} '2 w XV;`  
catch(IOException e){e.printStackTrace ();} ,}eRnl\  
catch(Exception e){e.printStackTrace ();} sM #!Xl;  
} V h Z=,m  
;r gH}r  
x-w`KFS  
private void processErrorCode(int nErrorCode) j2< !z;2  
{ eo>/  
System.err.println("Error Code : " + nErrorCode); dCa}ITg  
} [q|?f?Zl  
:D<:N*9i  
unCt4uX^  
//停止文件下载 Vf"O/o}hq,  
public void siteStop() x{=[w`  
{ ERUs0na]  
bStop = true; ;% /6Y~/  
for(int i=0;i<nStartPos.length;i++) q"{Up  
fileSplitterFetch.splitterStop(); !w @1!Xpn1  
=Jsg{vI  
<$RS*n  
} _8,vk-,'  
} I{`KKui<M  
//负责部分文件的抓取 gJ<@;O8zu0  
**FileSplitterFetch.java fBHkLRFH  
*/ = 4BLc  
package NetFox; 73&]En  
$ /}:P  
8#X?k/mzU  
import java.io.*; Qw3a"k-  
import java.net.*; ,[Dh2fPM,  
4w;r l(s  
cmwzKu%  
public class FileSplitterFetch extends Thread { kHt!S9r  
&:;/]cwj  
u@GRN`yn  
String sURL; //File URL nQ:ml  
long nStartPos; //File Snippet Start Position *,O :>Z5I  
long nEndPos; //File Snippet End Position +O;OSZ  
int nThreadID; //Thread's ID TSc~$Q]  
boolean bDownOver = false; //Downing is over }}kS~ w-#  
boolean bStop = false; //Stop identical a) I=U [  
FileAccessI fileAccessI = null; //File Access interface C ffTv  
UgF)J  
g i1}5DR  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )![f\!'PI  
{ n/KI"qa]9  
this.sURL = sURL; K[iY{  
this.nStartPos = nStart; &*jxI[  
this.nEndPos = nEnd; dAu^{1+2  
nThreadID = id; 1TK #eU  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 D)H?=G  
} +Fu@I{"A  
ZTQ$Ol+{ q  
NYSj^k;^(z  
public void run() 4@/q_*3o  
{ H B::0l<  
while(nStartPos < nEndPos && !bStop) sDzD 8as  
{ *b$z6.  
sf.E|]isW  
xHM&csL  
try{ M3ecIVm8(  
URL url = new URL(sURL); ir?Uw:/f  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bqZ?uvc3  
httpConnection.setRequestProperty("User-Agent","NetFox"); O4 +SD  
String sProperty = "bytes="+nStartPos+"-"; yDCooX0  
httpConnection.setRequestProperty("RANGE",sProperty); H3 A]m~=3  
Utility.log(sProperty); C$N4   
[oQ`HX1g  
V\iIvBpWg  
InputStream input = httpConnection.getInputStream(); q;1VF;<"vH  
//logResponseHead(httpConnection); Y(#d8o}}#  
]>VJ--fH  
RT.wTJS;  
byte[] b = new byte[1024]; WU+Jo@]y  
int nRead; "}]GQt< F  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _|^&eT-u  
{ d&[M8(  
nStartPos += fileAccessI.write(b,0,nRead); *pcbwd!/  
//if(nThreadID == 1) ;55tf l  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?L<UOv7;t  
} vWnHC  
vOvxQS}dBp  
P+*rWJ8gQ  
Utility.log("Thread " + nThreadID + " is over!"); y]z)jqX<  
bDownOver = true; ?1-n\ka  
//nPos = fileAccessI.write (b,0,nRead); ="#:=i]  
} Y\z^\k  
catch(Exception e){e.printStackTrace ();} zVc7q7E  
} \,@Yl.,+  
} V'HlAQr  
#VQGN2bK.  
'-nuH;r  
//打印回应的头信息 C$AIP\j- )  
public void logResponseHead(HttpURLConnection con) 3]:p!Y`$  
{ By51dk 7  
for(int i=1;;i++) S5*~r@8h  
{ *0Wi^f  
String header=con.getHeaderFieldKey(i); &9RW9u "  
if(header!=null) e-Ybac%  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6g~o3  
Utility.log(header+" : "+con.getHeaderField(header)); i-i}`oN  
else  MrKU,-  
break; \Age9iz&  
} :o.x=c B  
} <6}f2^  
c]g<XVI  
>'2w\Uk~:  
public void splitterStop() aowPji$H  
{ W[1f]w3  
bStop = true; PtPGi^  
} Dj,+t+|  
&G7)s%q  
w{:Oa7_A  
} C%95~\Ds  
+}`O^#<qLX  
<QkN}+B=  
/* UuOLv;v  
**FileAccess.java 6'No4[F 4n  
*//文件访问(定位,写) T ,O<LFv  
package NetFox; !q=Q~ea  
import java.io.*; RIVL 0Ig  
#T$'.M  
_Pfx_+  
public class FileAccessI implements Serializable{ S}v{^vR  
>F\rBc&  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 XTi0,e]5{u  
RandomAccessFile oSavedFile; $3]E8t  
long nPos; "zeJ4f  
{-v\&w  
>jrz;r  
public FileAccessI() throws IOException Jc"$p\ $-  
{ 11@2;vw  
this("",0); LjH&f 4mY  
}  $D, wO  
FkxhEat8  
TReM8Vd  
public FileAccessI(String sName,long nPos) throws IOException Z_^Kl76D  
{ x3I%)@-Z  
oSavedFile = new RandomAccessFile(sName,"rw"); c~pUhx1(  
this.nPos = nPos; o trTrh  
oSavedFile.seek(nPos); tXG4A$(2&  
} ~Q$c!=   
eRl?9  
:AqnWy  
public synchronized int write(byte[] b,int nStart,int nLen) 1 <qVN'[  
{ .X<"pd*@e  
int n = -1; 1n"+~N^\  
try{ RESGI}u  
oSavedFile.write(b,nStart,nLen); "13 :VTs[5  
n = nLen; s:jL/%+COZ  
} ;FgEE%  
catch(IOException e) `~aLSpB65  
{ U+RCQTo  
e.printStackTrace (); R/Dy05nloe  
} C_^R_  
7AtXG^lK  
#Zavdkw=d  
return n; /4-eoTxy  
} c@o/Cv  
/P8eI3R  
i:Z.;z$1  
} Bn#HJ17/#  
]N(zom_0d  
Dpp52UnT E  
/* T`'3Cp$q  
**SiteInfoBean.java d$?n6|4  
*/ ,f /IG.  
package NetFox; ?j4,^K3  
++{+ #s6  
Kt* za  
public class SiteInfoBean { / =Uv  
"$:y03V  
/?dQUu ^z  
private String sSiteURL; //Site's URL RY/ Z~]  
private String sFilePath; //Saved File's Path 73sAZa|  
private String sFileName; //Saved File's Name @qhg[= @  
private int nSplitter; //Count of Splited Downloading File y1"^S  
0&rH 9  
Mi/'4~0Y  
public SiteInfoBean() GLKN<2|2@y  
{//nSplitter的缺省值为5 5W]N]^v  
//default value of nSplitter is 5 f $@".  
this("","","",5); \$HB~u%dr  
} ~tj7zI6  
P2:Q+j:PX  
X"khuyT_  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8JFkeU%yO  
{ ah6F^Kpl{  
sSiteURL= sURL; %k;FxUKi  
sFilePath = sPath; +!V%Q  
sFileName = sName;  DIu72\  
this.nSplitter = nSpiltter; gmAKW4(  
z#E,96R  
NW>:Lz ?"  
} ~ {7N TW  
2|NyAtPb5  
QsF<=b~  
public String getSSiteURL() \FY De  
{ XOU-8;d  
return sSiteURL; eg~^wi  
} q}A3"$-F  
+q=jB-eIx  
S~(VcC$K  
public void setSSiteURL(String value) <$3nD b-  
{ . ;@) 5"  
sSiteURL = value; U#1yl6e\I  
} &lfF!   
#/v_ h6$  
Y)5uK:)^  
public String getSFilePath() uy-Ncy  
{ xo 'w+Av  
return sFilePath; eWk2YP!  
} zt?w n* _  
NizJq*V>  
98}vbl31j  
public void setSFilePath(String value) 6=lQT 9u{  
{ fu "z%h]   
sFilePath = value; vAhO!5]>\  
} :pjK\  
eD1MP<>h  
 p|8Fl  
public String getSFileName() rHdP4:n  
{ 7<Js'\Z  
return sFileName; |Gs-9+'y  
} 2?nyPqT3AM  
:@8.t,|  
! tPK"k  
public void setSFileName(String value) 1:s~ ]F@  
{ ;Wh[q*A  
sFileName = value; [^=8k2  
} `IRT w"  
!9cPNIi  
+~{nU'  
public int getNSplitter() 0m!ZJHe  
{ dZYJ(7%  
return nSplitter; nMoF;AdKm  
} Oc+L^}elJ  
4_:e+ ql  
td$6:)  
public void setNSplitter(int nCount) Cv7RCjMw  
{ ~HI0<;r=eL  
nSplitter = nCount; s ;Nu2aOp7  
} XUNgt(OGR'  
} & ~G  
<4HuV.K  
 F%$Ws>l  
/* 00wH#_fm  
**Utility.java uOUw8  
*/ 2}\sj'0&  
package NetFox; ^B=z_0 *  
n?fC_dy  
H.~+{jTr  
public class Utility { g^^m a}i  
C4TD@  
pG=zGx4  
public Utility() s"F,=]HQ!G  
{ oqo8{hrdHk  
)4~XZt1r  
G%/cV?18  
} Y k6WSurw  
RXvcy<  
//线程睡眠 H$iMP.AK  
public static void sleep(int nSecond) \/%Q PE8  
{ u}0t`w:  
try{ xW )8mv?4n  
Thread.sleep(nSecond); `fVA. %  
} (P] ^5D  
catch(Exception e) V"p*Jd"w  
{  ]= D  
e.printStackTrace (); *4\ub:9  
} #!j&L6  
} sJYX[  
jo:p*Q "F  
//日志 bbA<Zp  
public static void log(String sMsg) ~;a* Oxt  
{ )p](*Z^  
System.err.println(sMsg); GDe$p;#"9g  
} >%A=b}VS  
&G,v*5N8$K  
r|$g((g  
public static void log(int sMsg) "d*  
{ dQ o$^?  
System.err.println(sMsg); ` u)V 9{  
} 1fG@r%4  
} uB!P>v6  
O4URr  
t)b>f~  
/* :P'5_YSi  
**TestMethod.java IiU|@f~k  
*/ $S=OmdgR  
package NetFox; cv&hT.1  
z`6KX93  
05DtU!3O  
public class TestMethod { 7P(:!ce4-  
1O{67Pf  
RT 9|E80  
public TestMethod()  16{;24  
{ ///xx/weblogic60b2_win.exe c9K\K~bk  
try{ Jx,s.Z0@7,  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -O6o^Dk  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8;bOw  
SiteFileFetch fileFetch = new SiteFileFetch(bean); uu#+|ZD  
fileFetch.start(); o W [-?  
} 4^A'A.0  
catch(Exception e){e.printStackTrace ();} !b Km}1T  
<Z wEdq  
 yw^, @'  
} _z< q9:  
Cr"hu;  
<]J5AdJ  
public static void main(String[] args) wjs7K|PK  
{ q\G@Nn^  
new TestMethod(); -rrg?4  
} gNBI?xs`p  
} EyiM`)!5  
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