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
  • 11551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
/* FWG6uKv  
**SiteFileFetch.java os:A]  
*/ )9"_J9G  
package NetFox; OX?\<),  
import java.io.*; :fZ}o|t7  
import java.net.*; @v)p<r^M">  
!C3MFm{B  
pUQ/03dp  
public class SiteFileFetch extends Thread { E%,^Yvh/  
|Sy<@oq  
R5 - @  
SiteInfoBean siteInfoBean = null; //文件信息Bean YSic-6z0Ms  
long[] nStartPos; //开始位置 ?kH8Lw~{5W  
long[] nEndPos; //结束位置 ?IqQ-C)6D  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 %4,O 2\0?&  
long nFileLength; //文件长度 (mTE;s(  
boolean bFirst = true; //是否第一次取文件 lvBx\e;7P  
boolean bStop = false; //停止标志 J$GUB3 G  
File tmpFile; //文件下载的临时信息 bB1UZ O  
DataOutputStream output; //输出到文件的输出流 1AM!8VR2  
[ 0KlC1=  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) IYS)7`{]  
public SiteFileFetch(SiteInfoBean bean) throws IOException L\xk:j1[  
{ xSsa(b  
siteInfoBean = bean; 7e|s wJ>4  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ;Q OBBF3HG  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); %7IugHH9y  
if(tmpFile.exists ()) :OhHb #D  
{ 6z#acE1)M  
bFirst = false; !Sh&3uy_qN  
read_nPos(); pz\ +U7  
} t(NI-UXBp  
else 4U+xb>  
{ i@)i$i4  
nStartPos = new long[bean.getNSplitter()]; d iL +:H  
nEndPos = new long[bean.getNSplitter()]; >~[c|ffyo/  
} 0ghGBuv1s  
+./H6!  
' g=  
tl,.fjZn  
} .oYl-.E>&  
dJeNbVd  
bMg(B-uF7  
public void run() t{^*6XOcJ  
{ QwJV S(Gs4  
//获得文件长度 A+ZK4]xb  
//分割文件 \E72L5nJW  
//实例FileSplitterFetch Y)0*b5?1r  
//启动FileSplitterFetch线程 B}Z63|/N  
//等待子线程返回 1PVtxL?1P  
try{ Wu c S:8#|  
if(bFirst) DCIxRPw  
{ C*)3e*T*  
nFileLength = getFileSize(); )t0$qd ]  
if(nFileLength == -1) ~dgDO:)  
{ GK )?YM  
System.err.println("File Length is not known!"); #%iDT6  
} 5[k/s}g  
else if(nFileLength == -2) U\4g#!qj  
{ n$x c];j  
System.err.println("File is not access!"); R]c+?4J  
} "pi=$/RD9  
else +7D|4  
{ WejY y|  
for(int i=0;i<nStartPos.length;i++) bH7X'%r  
{ [')m|u~FS4  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ddJQC|xR}  
} !;&p"E|b#  
for(int i=0;i<nEndPos.length-1;i++) jaTh^L  
{ ,&]S(|2%>t  
nEndPos = nStartPos[i+1]; H*RC@O_hv  
} 7 E r23Q  
nEndPos[nEndPos.length-1] = nFileLength; 2h|MXI\g  
} `18qbot  
} :1cV;gJ  
.0S~872  
#|Y5,a ,{  
//启动子线程 [-65PC4aN  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; eJF5n#  
for(int i=0;i<nStartPos.length;i++) b3&zjjQ  
{ bR*-Ht+wd  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1L%CJ+Q#0i  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), jqWu  
nStartPos,nEndPos,i); FOv=!'S o  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w k(VR  
fileSplitterFetch.start(); /f:dv?!km  
} fM]+SMZy  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ypbe!Y<i]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); f/ ?_  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", k$R~R-'  
nEndPos = " + nFileLength); N=4G=0 `ke  
// fileSplitterFetch[nPos.length-1].start(); s>B5l2Q4  
v~f HYa>  
?J%1#1L"/  
//等待子线程结束 0[R L>;D:  
//int count = 0; "Q}#^h]F  
//是否结束while循环 Ttu2skcv  
boolean breakWhile = false; ;kFDMuuO  
?Nup1 !D  
(|[2J3ZET  
while(!bStop) ;+W# 5<i  
{ dbwe?ksh  
write_nPos(); hEA<o67  
Utility.sleep(500); }6p@lla,%]  
breakWhile = true; iQ tN Aj  
kW2sY^Rg  
fV &KM*W*@  
for(int i=0;i<nStartPos.length;i++) n&{Dq}q  
{ 0ZT5bg_M  
if(!fileSplitterFetch.bDownOver) 5m*iE*+  
{ K#%&0D!  
breakWhile = false; Gy9$wH@8  
break; (_niMQtF}  
} n G,A@/N  
} #^`4DhQ/ 1  
if(breakWhile) zcel|oz)  
break; X^T:8npxt  
-|J"s$yO4  
W^0w  
//count++; KX76UW   
//if(count>4) NO~*T?&  
// siteStop(); _K`wG}YIE  
} Q}1 R5@7  
6TQoqH8@U  
x*![fK  
System.err.println("文件下载结束!"); !9u|fnC9  
} 6DM$g=/ '  
catch(Exception e){e.printStackTrace ();} 8qY79)vD4E  
} |*oZ _gI  
7F zA*  
%j:]^vqFA  
//获得文件长度 bt"W(m&f  
public long getFileSize() ~T ]m>A!  
{ D2<fw#  
int nFileLength = -1; aUzBV\Yd}  
try{ r;/4F/6"  
URL url = new URL(siteInfoBean.getSSiteURL()); j.C`U(n}`  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _a5d?Q9Z  
httpConnection.setRequestProperty("User-Agent","NetFox"); T?:Rdo!:u  
O;z,qo X  
I CZ4 A{I  
int responseCode=httpConnection.getResponseCode(); t0/p]=+.p/  
if(responseCode>=400) dq7x3v^"ZG  
{ |2?'9<  
processErrorCode(responseCode); I, -hf=-  
return -2; //-2 represent access is error kjW+QT?T&  
} 8 BY j  
zAK+8{,  
3[\iQ*d }B  
String sHeader; &)8:h+&Z  
ZW-yP2  
_p# CwExuy  
for(int i=1;;i++) ;o^eC!:/%  
{ 2VF%@p  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Fgkajig  
//Utility.log(in.readLine()); Ager$uC  
sHeader=httpConnection.getHeaderFieldKey(i); Ipf|")*  
if(sHeader!=null) {G|,\O1  
{ 3 ;)>Fs;  
if(sHeader.equals("Content-Length")) ?Eg(Gu.J  
{ *meZ8DV2DH  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +!k&Yje  
break; $"`- ^  
} kd=GCO  
} dA-2%uJ  
else RSr %n1  
break; m$`RcwO  
} Jpj}@,  
} R?v>Q` Qi  
catch(IOException e){e.printStackTrace ();} !zux z  
catch(Exception e){e.printStackTrace ();} Mx6@$tQ%  
;>5 06jZ  
e8y;.D[2  
Utility.log(nFileLength); t2EHrji~  
.clP#r{U  
~u)}ScTp  
return nFileLength; 7q?9Tj3  
} LG-y]4a}  
cmBB[pk\  
#%`|~%`{:  
//保存下载信息(文件指针位置) .9,zL=)Ba  
private void write_nPos() JCz@s~f\y  
{ Dakoqke  
try{ 'HT7_$?*  
output = new DataOutputStream(new FileOutputStream(tmpFile)); @_U;9)  
output.writeInt(nStartPos.length);  u*e.yN  
for(int i=0;i<nStartPos.length;i++) P6E3-?4j  
{ 3Th'paMG  
// output.writeLong(nPos); @WJg WJm  
output.writeLong(fileSplitterFetch.nStartPos); 0FGe=$vD  
output.writeLong(fileSplitterFetch.nEndPos); s<*XN NE7  
} 1lq(PGX)  
output.close(); ]NjX?XdX<  
} VK}fsOnj0  
catch(IOException e){e.printStackTrace ();} =2[7 E  
catch(Exception e){e.printStackTrace ();} C2@,BCR  
} ^sa#8^,K  
7P" | J\  
9w"h  
//读取保存的下载信息(文件指针位置) w<zIAQN  
private void read_nPos() Q&MZN);.  
{ 2}YOcnB  
try{ S7=Bd[4  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &@%W29:  
int nCount = input.readInt(); T~QWRBO  
nStartPos = new long[nCount]; dArDP[w  
nEndPos = new long[nCount]; !O-T0O   
for(int i=0;i<nStartPos.length;i++) y(Y!?X I  
{ 7+]=-  
nStartPos = input.readLong(); 8*8Zc/{  
nEndPos = input.readLong(); PH`9MXh  
} #6ri-n  
input.close(); J%x6  
} }~#pEX~j*  
catch(IOException e){e.printStackTrace ();} Em?d*z  
catch(Exception e){e.printStackTrace ();} :q=%1~Idla  
} $P>`m$(8  
p+l!6  
&$"i,~q^b  
private void processErrorCode(int nErrorCode) 3mYiQ2  
{ :80Z6F.k`  
System.err.println("Error Code : " + nErrorCode); t0z!DOODZP  
} ;w'D4p= P  
HOw -]JSP2  
+#GQ,  
//停止文件下载 $}lbT15a  
public void siteStop() A6GE,FhsG  
{ h]og*(  
bStop = true; ^[]}R:  
for(int i=0;i<nStartPos.length;i++) [P Q?#:r  
fileSplitterFetch.splitterStop(); v[#9+6P=  
K3m]%m2\  
'6Ay&A3N]  
} SxdE?uCUS  
} 0dhF&*h|L  
//负责部分文件的抓取 )_mr! z(S  
**FileSplitterFetch.java wB.Nn/p  
*/ wSb 1"a  
package NetFox; I"Ms-zs  
m_=$0m J$  
an4GSL  
import java.io.*; GKvN* SU=  
import java.net.*; f` :i.Sr  
L!=4N!j  
dYSr4p b  
public class FileSplitterFetch extends Thread { P8^hBv*  
4Fp0ZVT  
G"X8}:}  
String sURL; //File URL .uyGYj-C  
long nStartPos; //File Snippet Start Position ?"zY" *>4  
long nEndPos; //File Snippet End Position _/Gczy4)#  
int nThreadID; //Thread's ID D|rFu  
boolean bDownOver = false; //Downing is over Z-E`>  
boolean bStop = false; //Stop identical @?=|Y  
FileAccessI fileAccessI = null; //File Access interface -:30:oq  
SV:4GVf  
T^T[$26  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException RE =`  
{ j'%$XvI  
this.sURL = sURL; 5m?8yT}  
this.nStartPos = nStart; SG-'R1 J  
this.nEndPos = nEnd; f8M$45A'  
nThreadID = id; `D`sr[3n  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 pX&pLaF  
} *H?!;u=8  
_@ *+~9%8p  
58%#DX34M  
public void run() F#5B<I  
{ w=LP"bqlI  
while(nStartPos < nEndPos && !bStop) bHg,1y)UC  
{ 0KMctPT]p  
}-~X4u#   
~=8uN<  
try{ K?s+3  
URL url = new URL(sURL); vhsk 0$f  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Jrg2/ee,*  
httpConnection.setRequestProperty("User-Agent","NetFox"); #<e\QE'!  
String sProperty = "bytes="+nStartPos+"-"; u:m]CPz  
httpConnection.setRequestProperty("RANGE",sProperty); R  zf  
Utility.log(sProperty); X@k`3X  
U f|> (C  
R,9[hNHWGs  
InputStream input = httpConnection.getInputStream(); jeGj<m  
//logResponseHead(httpConnection); ,$'])A?$  
]Ar\c["  
UlAzJO6"  
byte[] b = new byte[1024]; S,<EEtXQ  
int nRead; {e+-vl  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N@Y ljz|  
{ C8 vOE`U,J  
nStartPos += fileAccessI.write(b,0,nRead); TjHwjRa  
//if(nThreadID == 1) K'X2dG*  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x9x E&  
} L=q+|j1>  
GN!qyT  
?t+5s]  
Utility.log("Thread " + nThreadID + " is over!"); wk6NG/<  
bDownOver = true; hoQs @[  
//nPos = fileAccessI.write (b,0,nRead);  .&9 i  
} oS7(s  
catch(Exception e){e.printStackTrace ();} _)]+hUw Y  
} +hE(Ra#  
} NPd%M  
^s@8VAwi  
Qb)C[5a}  
//打印回应的头信息 ~mO62(8m  
public void logResponseHead(HttpURLConnection con) 1gmt2>#v%  
{ 34wkzu  
for(int i=1;;i++) i&vaeP25)  
{ F B?UZ  
String header=con.getHeaderFieldKey(i); ;=<-5;rI  
if(header!=null) Q %wY  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7zHh@ B:]  
Utility.log(header+" : "+con.getHeaderField(header)); wMdal:n^  
else wKi^C 8Z2  
break; =egW  
} >m# e:[N  
} [Z~ 2  
W -  
g8w2Vz2/  
public void splitterStop() "=6v&G]U4  
{ /DqLrA  
bStop = true; y_HN6  
} -jn WZ5.  
BWrv%7  
yuDZ~0]R  
} >~`r:0',  
5Q 'i2*j  
+&Hr4@pgW  
/* j:,NE(DF  
**FileAccess.java vjQb%/LWl  
*//文件访问(定位,写) {5d9$v7k4  
package NetFox; Hew d4k  
import java.io.*; n @?4b8"  
hUD7_arKF  
vk>b#%1{  
public class FileAccessI implements Serializable{ fx@j?*Qb  
"H&"(=  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Fe.t/amS/  
RandomAccessFile oSavedFile; 0vVV%,v  
long nPos; =) E,8L  
H)aQ3T4N5  
K]U;?h&CZc  
public FileAccessI() throws IOException Q2A7mGN  
{ 8E8N6  
this("",0); =56T{N  
} HLBkR>e  
2_ :n  
eeHP&1= 7  
public FileAccessI(String sName,long nPos) throws IOException @x eAc0.^  
{  Y!WG)u5  
oSavedFile = new RandomAccessFile(sName,"rw"); #U*_1P0h  
this.nPos = nPos; PG8^.)]M  
oSavedFile.seek(nPos); ?-tVSRKQ  
} hXb%;GL  
'{ [5M!B  
k ^ YO%_  
public synchronized int write(byte[] b,int nStart,int nLen) aA'|Rg,  
{ Qj3a_p$)P  
int n = -1; {8R"O{  
try{ h'$QC )P  
oSavedFile.write(b,nStart,nLen); 0W3i()  
n = nLen; 7HVZZ!>~  
} 7},)]da>,'  
catch(IOException e) VR  
{ _:+ KMR  
e.printStackTrace (); k"g._|G  
} (mtoA#X1:h  
U`o^mtW.  
(;%|-{7e-  
return n;  J*l4|^i<  
} (_4;') 9  
L{E^?iX  
yQ3OL#  
} W5^.-B,(K  
fK&e7j`qO  
6YuY|JD  
/* t+?P^Ok  
**SiteInfoBean.java '+ xu#R  
*/ RUr=fEH  
package NetFox; k<RZKwQc  
a=XW[TY1  
%'L;FPxB  
public class SiteInfoBean { v| z08\a[  
Qq0l* )mX  
(}!C4S3#  
private String sSiteURL; //Site's URL km:nE: |  
private String sFilePath; //Saved File's Path F5gObIJtuY  
private String sFileName; //Saved File's Name _-cK{  
private int nSplitter; //Count of Splited Downloading File TTI81:fku  
&h$|j  
MM{_Ur7Q  
public SiteInfoBean() W( *V2<$o  
{//nSplitter的缺省值为5 lm'Zy"~::  
//default value of nSplitter is 5 5 HV)[us  
this("","","",5); K.>wQA&  
} 7z~Ghz  
(UEXxUdQ_Q  
-E&e1u,Mi  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6k])KlJ2;  
{ KSs1CF'i  
sSiteURL= sURL; Uhh l3%p  
sFilePath = sPath; XOb}<y)r~  
sFileName = sName; N:+ taz-  
this.nSplitter = nSpiltter; }GHxG9!z  
^E>CGGS4  
Kf7WcJ4b  
} j kn^Z":  
FT\?:wpKa  
h.tY 'F  
public String getSSiteURL() 0x)dnq\  
{ M<8ML!N0;t  
return sSiteURL; 9\O(n>  
} ]j.k?P$U}  
oJ;rc{n-  
aSaAC7sFk  
public void setSSiteURL(String value) eS!C3xC;J]  
{ fu\s`W6f&  
sSiteURL = value; b#Kq[}  
} *FgJ|y6gk  
@ Gjny BJ  
hol<dB  
public String getSFilePath() OHp5z? z  
{ z[!x:# q8`  
return sFilePath; ahIE;Y\j'  
} Z>A{i?#m  
H30OUrD  
o$_93<zc  
public void setSFilePath(String value) IS_Su;w>4  
{ )r!e2zc=Q  
sFilePath = value; d!{7r7ob\  
} oh}^?p  
r4k nN 2:  
RtF8A5ys  
public String getSFileName() z:G}>fk5  
{ o42`z>~  
return sFileName; r?p{L F  
} ,ECAan/@  
`bP?o  
6M><(1fT  
public void setSFileName(String value) -}<g-*m"q  
{ l)@:T|)c  
sFileName = value; 6$ e]i|e  
} f$D@*33ft  
E/ O5e(h  
!EFBI+?&  
public int getNSplitter() 3IyZunFT  
{ h`?k.{})M  
return nSplitter; L$JI43HZ  
} R^{xwI  
/7p>7q 9g  
|cTpw1%I~  
public void setNSplitter(int nCount) #8?^C]*{0  
{ z}APR@?`n8  
nSplitter = nCount; t.=Oj  
} 1X@b?6  
} ,YlQK;  
do' ORcZ  
XS/n>C  
/* B7 c[ 4  
**Utility.java yh!B!v'  
*/ euZ(}+N&  
package NetFox; YX;nMyD?~  
/2w@ K_Px6  
>h7$v~nra  
public class Utility { |\{Nfm=:%  
BJIQ zn3  
5b fb!7-[i  
public Utility() _;G=G5r  
{ $^$ECDOTB  
uC[d%v`  
)F E8D  
} Wm>b3:  
kIM C~Z  
//线程睡眠 -A;w$j6*  
public static void sleep(int nSecond) okDJ(AIV+  
{ 1f;or_f#k?  
try{ k/^g*  
Thread.sleep(nSecond); ,wT g$ g-$  
} ewQe/Fq  
catch(Exception e) C1ZyB"{  
{ jZ#UUnR%  
e.printStackTrace (); B(Y.`L? %E  
} Q?]w{f(  
} A\g%  
=h[yA f  
//日志 9l l|JeNi  
public static void log(String sMsg) GC?S];PL  
{ T9y768%  
System.err.println(sMsg); %yhI;M^  
} u*k*yWdr  
9fCO7AE0#  
:B^mV{~  
public static void log(int sMsg) #NM JZ  
{ L5C2ng>  
System.err.println(sMsg); 4tnjXP8  
} 9<Ag1l  
} T0?uC/7H  
%^U"Spv;  
bQV("~#  
/* 25&nwz  
**TestMethod.java gPp(e j7  
*/ ex0oAt^  
package NetFox; tx)OJY  
_Z.;u0Zp8  
xv&S[=Dt  
public class TestMethod { qxSs ~Qc  
iP,v=pS6  
>F|qb*Tm7  
public TestMethod() -;<>tq'3`  
{ ///xx/weblogic60b2_win.exe jQs*(=ls  
try{ #!1IP~  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); j$0zD:ppW  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); IO6MK&R  
SiteFileFetch fileFetch = new SiteFileFetch(bean); W/a,.M  
fileFetch.start(); zM\IKo_"  
} gE1|lY$NL  
catch(Exception e){e.printStackTrace ();} }M?|,N6  
bkkSIl+Q  
c+wuC,  
} <H-tZDh5  
-B,cB  
ysl8LK   
public static void main(String[] args) ,b4~!V  
{ EqoASu  
new TestMethod(); iA&oLu[y3  
} ^+URv  
} /Go>5 B>  
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
批量上传需要先选择文件,再选择上传
认证码:
验证问题:
10+5=?,请输入中文答案:十五