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
  • 8332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
/* M(U<H;Csk  
**SiteFileFetch.java ]o?r( 1  
*/ f=hT o!i  
package NetFox; z'&tmje[?  
import java.io.*; U1;&G  
import java.net.*; z7_h$v  
\C<'2KZR,  
{|B 2$1':  
public class SiteFileFetch extends Thread { A~X| vW  
"F:V$,mJ  
G{74o8  
SiteInfoBean siteInfoBean = null; //文件信息Bean (B0QBDj!  
long[] nStartPos; //开始位置 b5)a6qtb  
long[] nEndPos; //结束位置 7{lWg x  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 q.kDx_  
long nFileLength; //文件长度 f=A`{ 8^  
boolean bFirst = true; //是否第一次取文件  r m  
boolean bStop = false; //停止标志 0uu)0:  
File tmpFile; //文件下载的临时信息 VHm.uL_UW  
DataOutputStream output; //输出到文件的输出流 @TJ2 |_s6]  
a0&L,7mu<'  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) * hmoi  
public SiteFileFetch(SiteInfoBean bean) throws IOException *]:J@KGf  
{ ;(@' +"  
siteInfoBean = bean; muMd9\p  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); oU|_(p"e|  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 88KQ) NU  
if(tmpFile.exists ()) ^c]c`w  
{ 9qk J<  
bFirst = false; g(C/J9J  
read_nPos(); K5HzA1^  
} H`s[=Y,m  
else ws<p BC,m  
{ .*B@1q  
nStartPos = new long[bean.getNSplitter()]; E[Q2ZqhgbP  
nEndPos = new long[bean.getNSplitter()]; wGw<z[:f  
} 'Q"Mu  
O7oq1JI]Y  
uD\rmO{  
3 MCV?"0  
} $ {e5Ka  
'cqY-64CJZ  
SLz;5%CPV  
public void run() o@L2c3?c5  
{ hkOFPt&  
//获得文件长度 y3':x[d  
//分割文件 _jb&=f8  
//实例FileSplitterFetch A=sz8?K+`  
//启动FileSplitterFetch线程 [!#}#  
//等待子线程返回 G- |  
try{ 67Ev$a_d"  
if(bFirst) #&b<D2d  
{ cTQ._|M  
nFileLength = getFileSize(); ITy/h]0  
if(nFileLength == -1) ?pWda<&  
{ N/eus"O;  
System.err.println("File Length is not known!"); " {X0&  
} @&x'.2[nv  
else if(nFileLength == -2) LYr9a(  
{ |]~],  
System.err.println("File is not access!"); mQ9y{}t=4  
} LrT? ]o  
else mV0u:ws  
{ 7x]q>Y8T  
for(int i=0;i<nStartPos.length;i++) -jzoGzC3  
{ U]W "  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); {55f{5y3 c  
} H<tU[U=G  
for(int i=0;i<nEndPos.length-1;i++) "xNP"S  
{ i91k0q*di  
nEndPos = nStartPos[i+1]; TR%8O;  
} 7m%[$X`  
nEndPos[nEndPos.length-1] = nFileLength; BMtk/r/  
} shEAr*u  
} N8DouDq  
\Xe{vlo>h  
r$<M*z5q(\  
//启动子线程 G#~U\QlG-  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yg4#,4---b  
for(int i=0;i<nStartPos.length;i++) ;oO_5[,M  
{ C~WWuju'  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A-, hm=?  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =b8u8*ua  
nStartPos,nEndPos,i); |h\A5_0_  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c D .;  
fileSplitterFetch.start(); X3] [C  
} 9e4`N"#,lI  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), QQ=Kj%R  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <\$?.tTZ {  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", j'OXT<n*  
nEndPos = " + nFileLength); At'M? Q@v  
// fileSplitterFetch[nPos.length-1].start(); $3g M P+  
"<Yxt"Z4  
<g&.UW4  
//等待子线程结束 ,g4T>7`&U%  
//int count = 0; mi1^hl'2  
//是否结束while循环 $KhD>4^ jL  
boolean breakWhile = false; RY3=UeoF  
+~|Jn_:A f  
G.$KP  
while(!bStop) fQ1Dp  
{ I Bko"|e@  
write_nPos(); mmG]|Cl@  
Utility.sleep(500); F8#MI G   
breakWhile = true; Vvp{y  
I2-ue 63 ?  
~'|^|*}~Dj  
for(int i=0;i<nStartPos.length;i++) hgbf"J6V8  
{ VrWQ]L  
if(!fileSplitterFetch.bDownOver) QpA$='  
{ #R7hk5/8n}  
breakWhile = false; 1Y%lt5,*  
break; -0TI7 @  
} HXX9D&c4R  
} a^\ F9^j  
if(breakWhile) g}IOHE  
break; zl|+YjR  
r;{ggwY&J  
$Ld-lQsL  
//count++; 2 6 >9$S  
//if(count>4) &gr  T@  
// siteStop(); p8"C`bCf  
} cm!|A?-<  
.l|29{J  
stMxlG"d  
System.err.println("文件下载结束!"); tc{l?7P  
} Ov4=!o=  
catch(Exception e){e.printStackTrace ();} @$Yk#N;&(  
} 45x4JG  
ROvY,-?  
~*J <lln  
//获得文件长度 Dm$SW<!l|  
public long getFileSize() #DARZhU)  
{ um%s9  
int nFileLength = -1; '+ mI  
try{ wp'[AR}  
URL url = new URL(siteInfoBean.getSSiteURL()); lHPnAaue@  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yE.st9m  
httpConnection.setRequestProperty("User-Agent","NetFox"); -[&Z{1A4x4  
=T#hd7O`V  
8k)*f+1o  
int responseCode=httpConnection.getResponseCode(); ,1cpV|mAr  
if(responseCode>=400) s];0-65)  
{ _00}O+GLM4  
processErrorCode(responseCode); -m[ tYp,q  
return -2; //-2 represent access is error xA<-'8ST  
} kM@e_YtpY  
bxO[y<|XL  
:'xZF2  
String sHeader; {<a)+S.6U  
sva-Sd8  
[z"oi'"fQ  
for(int i=1;;i++) )2 q r^)  
{ !I\eIV>0b  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~C3J-z<  
//Utility.log(in.readLine()); tOte[~,  
sHeader=httpConnection.getHeaderFieldKey(i); |eg8F$WU  
if(sHeader!=null) xi4b;U j  
{ W$Xr:RU  
if(sHeader.equals("Content-Length")) PW iuM=E  
{ .:4*HB  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z\]LG4N?  
break; v~W ;&{  
} qx9; "Ut  
} c<~DYe;;  
else mkPqxzxbrL  
break; tk:nth  
} j^v<rCzc (  
} ]Nw ]po+  
catch(IOException e){e.printStackTrace ();} m5a'Vs  
catch(Exception e){e.printStackTrace ();} B*E"yB\NV  
I[gPW7&S@  
W voIh4]  
Utility.log(nFileLength); 9$qw&j[  
-e?n4YO*\  
VKw.g@BY  
return nFileLength; XR p60i6f  
} lqgR4  !  
2^75|Q  
{?++T 0  
//保存下载信息(文件指针位置) KY0<N 9{  
private void write_nPos() &U CtyCz  
{ n5efHJU  
try{ L?P[{Ohh/  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^|vP").aQm  
output.writeInt(nStartPos.length); Fp"c {  
for(int i=0;i<nStartPos.length;i++) 9b&;4Yq!f  
{ b$pCp`/MT  
// output.writeLong(nPos); /J Y6S  
output.writeLong(fileSplitterFetch.nStartPos); 1}SON4U  
output.writeLong(fileSplitterFetch.nEndPos); k_Sm ep  
} 7q 5 \]J[  
output.close(); ?)-anoFyVW  
} ?' mP`9I  
catch(IOException e){e.printStackTrace ();} 0LP0q9S:9  
catch(Exception e){e.printStackTrace ();} EP<{3f y  
} ?B)e8i<[f  
)7-mALyW  
WP Gp(X w  
//读取保存的下载信息(文件指针位置) ,`'A"]"  
private void read_nPos() (lq%4h  
{ j~=<O<P  
try{ sFvYCRw /  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); n=0^8QQ  
int nCount = input.readInt(); u-bgk(u  
nStartPos = new long[nCount]; +afkpvj8  
nEndPos = new long[nCount]; Sj*W|n\gj  
for(int i=0;i<nStartPos.length;i++) M0e&GR8<z>  
{ kmlO}0  
nStartPos = input.readLong(); u[4h|*'"|  
nEndPos = input.readLong(); [H9<JdUZ  
} V$iA3)7W%  
input.close(); /,j'V r\"  
} 8/y8tMm]  
catch(IOException e){e.printStackTrace ();} J-azBi  
catch(Exception e){e.printStackTrace ();} mi5bk>o  
} /xr75|-8  
`#r/L@QI  
x>Dix1b:.  
private void processErrorCode(int nErrorCode) 5p-vSWr !  
{ +# !?+'A  
System.err.println("Error Code : " + nErrorCode); BLt_(S?Z`  
} (JE&1 @  
/}%C'  
o/vD]Fs  
//停止文件下载 zW hzU|=8  
public void siteStop() aW;)-0+  
{ t-iQaobF  
bStop = true; _`laP5~  
for(int i=0;i<nStartPos.length;i++) hv#LKyp%  
fileSplitterFetch.splitterStop(); ^)$T`  
7s{['t  
}s#4m  
} _W,?_"[R=  
} rJtk4hOF  
//负责部分文件的抓取 P.=Dd"La  
**FileSplitterFetch.java 4{ZVw/VP,-  
*/ yFDt%&*n^  
package NetFox; naeppBo  
zP@\rZ@4  
onS4ZE3B  
import java.io.*; *13-)yfd  
import java.net.*; M0)ZJti  
Fa </  
OU^I/TU  
public class FileSplitterFetch extends Thread { &sXk!!85:  
D$D;'Kij  
Pp4Q)2X  
String sURL; //File URL Lm0q/d2|\X  
long nStartPos; //File Snippet Start Position `d x.<R#,  
long nEndPos; //File Snippet End Position qjf4G[]!  
int nThreadID; //Thread's ID O -p^S  
boolean bDownOver = false; //Downing is over <K/iX%b?  
boolean bStop = false; //Stop identical >Il{{{\>  
FileAccessI fileAccessI = null; //File Access interface :g-vy9vb  
Y8fel2;  
!NKPy+v  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException w2`JFxQ^x  
{ 62[_u]<Yub  
this.sURL = sURL; 6pZ/C<Y|W  
this.nStartPos = nStart; 6$csFW3R  
this.nEndPos = nEnd; X&@>M}  
nThreadID = id; wLg@BSC.  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Y]B9*^d<  
} q'Y)Y(d  
u=#_8e(9Z  
Cs,t:ajP  
public void run() ,ob)6P^rw  
{ Q%V530 P;  
while(nStartPos < nEndPos && !bStop) m8gU8a"(  
{ O"RIY3m  
/$FpceB!W  
"Gq%^^ *  
try{ :&RpB^]  
URL url = new URL(sURL); I Vw'YtZ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wc}4:~  
httpConnection.setRequestProperty("User-Agent","NetFox"); <c [X^8   
String sProperty = "bytes="+nStartPos+"-"; KJV],6d  
httpConnection.setRequestProperty("RANGE",sProperty); FuFICF7+C  
Utility.log(sProperty); Rp}Sm,w(  
Q[aBxy (  
H^$7=  
InputStream input = httpConnection.getInputStream(); COH>B1W@  
//logResponseHead(httpConnection); &>ykkrY  
_w%{yF6   
A{DE7gp!  
byte[] b = new byte[1024]; Z[\nyj  
int nRead; ),-MrL8c%  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _M- PF$  
{ /AUX7 m.8  
nStartPos += fileAccessI.write(b,0,nRead); ? 8S~R  
//if(nThreadID == 1) TLz>|gr  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); id1gK(F8H  
} 'puiahA  
.bRDz:?j  
bHz H0v]:  
Utility.log("Thread " + nThreadID + " is over!"); cNl$ vP83z  
bDownOver = true; -e*(+  
//nPos = fileAccessI.write (b,0,nRead); - KaU@t  
} cA!o xti  
catch(Exception e){e.printStackTrace ();}  '^,|8A2  
} uC 2{ Mmy  
} 0qN+W&H  
rp!{QG  
|W|RX3D  
//打印回应的头信息 D}nRH@<`  
public void logResponseHead(HttpURLConnection con) "Y=4Y;5q  
{ 3rx 8"  
for(int i=1;;i++) d{]2Q9g  
{ ?T'a{ ~]R  
String header=con.getHeaderFieldKey(i); ey U*20  
if(header!=null) /@LUD=  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mnq1WU;<  
Utility.log(header+" : "+con.getHeaderField(header)); __-V_(/b,x  
else ^'hh?mL  
break; }>'1Qg  
} E*}1_,q)  
} K|rG&#1J  
7x(z  
-Vjrh/@  
public void splitterStop() Tpp?(lT7r  
{ XhJYsq]]J  
bStop = true; .:SY:v r  
} ?]58{O(?c  
9XN/ w p  
:b(Nrj&TQ[  
} "J%dI9tM{  
0NyM|  
?T8^tGD[  
/* ]_:j+6i  
**FileAccess.java 5R*55@)  
*//文件访问(定位,写) #pWeMt'  
package NetFox; VP"C|j^I  
import java.io.*; ;:w0%>X^  
p+xjYU4^C  
0G #s/u#  
public class FileAccessI implements Serializable{  Y?IXV*J  
dpB\=  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 x I(X+d``  
RandomAccessFile oSavedFile; Y;>D"C..  
long nPos; ~s) `y2Y  
<USr$  
z_t%n<OvK  
public FileAccessI() throws IOException <io;d$=}  
{ GFYHt!&[\  
this("",0); UiN6-{v<2  
} 91}kBj  
h@D!/PS  
PKX Tj6hj)  
public FileAccessI(String sName,long nPos) throws IOException l1" *  
{ y- @{  
oSavedFile = new RandomAccessFile(sName,"rw"); m+pFU?<|  
this.nPos = nPos; s )7sgP  
oSavedFile.seek(nPos); 3;wOA4ur  
}  <4 D.H  
.2QZe8"  
) t$o0!  
public synchronized int write(byte[] b,int nStart,int nLen) k'-5&Q  
{ ^:^8M4:  
int n = -1; :<R"Kk@  
try{ ]+@I] \S4  
oSavedFile.write(b,nStart,nLen); $/$ 5{<  
n = nLen; Ab:+AC5{  
} UO_tJN#X  
catch(IOException e) 5>S)+p  
{ I_iXu;UX  
e.printStackTrace (); xC-&<s  
} _{y4N0  
e<HHgC#J  
}/.GB5Ej  
return n; [> LL  
} sx@ %3j  
'2xfU  
*.A{p ;JC(  
} 3mLtnRX[m  
]}>uvl^l  
W$Op/  
/* *dX 7  
**SiteInfoBean.java t4r%EP|Zt  
*/ +YCKd3/  
package NetFox; yFjjpEpnFt  
"D7wtpJ  
50NLguE  
public class SiteInfoBean { #A9rI;"XI  
oO&R3zA1d  
*QP+p,L*  
private String sSiteURL; //Site's URL jLF,R7t  
private String sFilePath; //Saved File's Path iJ!p9E*(  
private String sFileName; //Saved File's Name k/2TvEV3=  
private int nSplitter; //Count of Splited Downloading File -=a,FDeR  
nn{PhyK  
Xx e07J~  
public SiteInfoBean() 3 cF4xUIZ  
{//nSplitter的缺省值为5 !A&>Eeai  
//default value of nSplitter is 5 @ACq:+/Q c  
this("","","",5); raB', Vp  
} +`l)W`zX  
2HF_kYZ  
Y3?)*kz%  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) XSe\@t~&g  
{ &W$s-qf".  
sSiteURL= sURL; &a?k1R>  
sFilePath = sPath; @$!rgLyL[  
sFileName = sName; sJ5Ws%q  
this.nSplitter = nSpiltter; J6RzN'j  
,^uQw/  
Q> J9M` a  
} }C<$q  
W?R@ eq.9  
:L5k#E "u  
public String getSSiteURL() i{4J$KT  
{ 2su/I  
return sSiteURL; 4-JyK%m,0  
} W9/HM!  
!]t5(g_  
`xF^9;5mi  
public void setSSiteURL(String value) Qk] ^]I  
{ agp7zw=N  
sSiteURL = value; EdC/]  
} tM3Q;8gB!  
a?8boN(  
5 =Op%  
public String getSFilePath() 5LJ0V  
{ H_d^Xk QZ  
return sFilePath; Rh#QPYPq  
} M992XXd  
)h`8</#m{  
MWJ}  
public void setSFilePath(String value) s&F& *5W  
{ ';KWHk8C  
sFilePath = value; 84A:Rd'k3)  
} _DLELcH Y  
0rCQz3gh1  
uG=~k O  
public String getSFileName() ~+CEek  
{ fRomP-S  
return sFileName; r&ux|o+  
} lkJ"f{4f  
QyD(@MFxb  
<N,:w`g#  
public void setSFileName(String value) L-1#n  
{ uo-1.[9ds  
sFileName = value; eNu]K,rT  
} L*(`c cU  
G|.6%-  
#&K?N  
public int getNSplitter() Ox9M![fC  
{ UOn:@Qn  
return nSplitter; 8'#L+$O &N  
} ErxvGB(2  
 EHk$,bM  
_@OS,A  
public void setNSplitter(int nCount) KtD XB>  
{ 9NeHN@D)  
nSplitter = nCount; Y@ X>ejk"  
} )LTX.Kg  
} V)A7q9Bum  
xv~Sk2Z+d  
P71] Z  
/* W:JR\KKU  
**Utility.java o'K= X E  
*/ !nL>Ly  
package NetFox; KpC!C9  
@|D#lBm  
[,sm]/Xlc  
public class Utility { ^X ~S}MX  
ti!kJ"q  
2B b,ZC*  
public Utility() Hq#q4Y  
{ ]DjnzClx  
Scfe6+\EW  
$ D.*r*c6  
} u4|) A4n  
jM: |%o  
//线程睡眠 L [&|<<c  
public static void sleep(int nSecond) 1|:'jK#gE  
{ /<1zzeHRSD  
try{ +h@ZnFp3  
Thread.sleep(nSecond); oc;4;A-;`c  
} SvQ!n4 $  
catch(Exception e) *yYeqm  
{ 8(g}/%1mt3  
e.printStackTrace (); p# JPLCs  
} ';xp+,'}\  
} #=N6[:,  
@6b4YV h  
//日志 uc aa;zj  
public static void log(String sMsg) eh}|Wd7J  
{ B*:W`}G]_c  
System.err.println(sMsg); ?-JW2 E"uT  
} Q7-'5s   
iLQ;`/j  
2=7:6Fw  
public static void log(int sMsg) )=AWgA  
{ jHk.]4&0  
System.err.println(sMsg); sKC(xO@L;`  
} ,*8)aZ1 k  
} gO#%*  W  
XZT|ID_u"  
O Ke 9/._  
/* JqV}$E"M2  
**TestMethod.java <[vsGUbc  
*/ ce:wF#Qs  
package NetFox; >Se-5QtLcf  
Kx02 2rgDU  
/0b7"Kr  
public class TestMethod { N ;Cs? C  
M[cAfu  
qtuT%?wT@Z  
public TestMethod() kRV]`'u,  
{ ///xx/weblogic60b2_win.exe dF7`V J2  
try{ W&HxMi  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @H}{?-XyA  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); T?CQgVR  
SiteFileFetch fileFetch = new SiteFileFetch(bean); =^z*p9ZB  
fileFetch.start(); [9yd29pQ]  
} ]e$n;tuW  
catch(Exception e){e.printStackTrace ();} 9<.8mW^68  
?}HZJ@:lB  
= u&dU'@q  
} f9t+x+ Z  
I#;.; %u  
3gYtu-1  
public static void main(String[] args) <?h(Dchq  
{ ~:*V'/2k  
new TestMethod(); #vc!SI  
} M zF,is  
} F~/~_9RJ  
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
温馨提示:欢迎交流讨论,请勿纯表情、纯引用!
认证码:
验证问题:
10+5=?,请输入中文答案:十五