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
  • 8938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
/* I]B[H6  
**SiteFileFetch.java c:f++||  
*/ 1u\kxlZ  
package NetFox; \[5mBuk  
import java.io.*; p}{V%!`_  
import java.net.*; oEuo@\U05v  
%. -nZC  
O,A}p:Pgs  
public class SiteFileFetch extends Thread { ab-MEN`5  
S&w(H'4N  
QnPgp(d <  
SiteInfoBean siteInfoBean = null; //文件信息Bean j6.'7f5M<H  
long[] nStartPos; //开始位置 Ze>Pg.k+  
long[] nEndPos; //结束位置 YkqauyV^  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 t 9Dr%#  
long nFileLength; //文件长度 Qx%]u8s  
boolean bFirst = true; //是否第一次取文件 R404\XGL  
boolean bStop = false; //停止标志 ~!G&K`u  
File tmpFile; //文件下载的临时信息 |Sf` Cs  
DataOutputStream output; //输出到文件的输出流 q7'[II;  
<1EmQ)B   
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) OJH:k~]0!  
public SiteFileFetch(SiteInfoBean bean) throws IOException @N0(%o&  
{ %M_5C4&6  
siteInfoBean = bean; %hqhi@q#  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Hxm CKW!  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); _-.~>C  
if(tmpFile.exists ()) ie+746tFW  
{ r31H Zx1^  
bFirst = false; I$7TnMug  
read_nPos(); gUq)M  
} l8_TeO  
else yt-F2Z&  
{ $CY B&|d  
nStartPos = new long[bean.getNSplitter()]; Mi5"XQ>/  
nEndPos = new long[bean.getNSplitter()]; &3;yho8v@  
} RL;>1Q,H  
J&IFn/JK$  
tt7l%olw  
G2x5%`   
} H@8g 9;+  
;_^ "}  
(n~ e2tZ/  
public void run() K)`\u7Bu  
{ L,F )l2  
//获得文件长度 G*f5B  
//分割文件 = +uUWJ&1G  
//实例FileSplitterFetch ?+bDFM}  
//启动FileSplitterFetch线程 [-bT_X  
//等待子线程返回 vG<JOxP  
try{ >iCkvQ  
if(bFirst) Qs*6wF  
{ Bi +a)_K  
nFileLength = getFileSize(); rl,6r u  
if(nFileLength == -1) uW,L<;HnQ  
{ t*? CD.S  
System.err.println("File Length is not known!"); gr/o!NC  
} Bkn- OG  
else if(nFileLength == -2) |x AwiF_  
{ wghz[qe  
System.err.println("File is not access!"); h69: Tj!  
} \c! LC4pE  
else FH'jP`  
{ \sIRV}Tk}N  
for(int i=0;i<nStartPos.length;i++) Cz\(.MWNZ  
{ [Q/')5b  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); U?6YY` A8  
} oK GFDl]3  
for(int i=0;i<nEndPos.length-1;i++) p,=:Ff}~  
{ "}bk *2  
nEndPos = nStartPos[i+1]; $rySz7NI  
} ^;2dZgJ4^  
nEndPos[nEndPos.length-1] = nFileLength; G~{xTpL  
} X^#.4:>.  
} $FgpFxz;  
.bOueB-  
Cl;B%5yl  
//启动子线程 dJ#. m  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @5%cP  
for(int i=0;i<nStartPos.length;i++) !P, 9Sg&5)  
{ / 4K*iq  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), EX[X|"r   
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), j/bebR}X  
nStartPos,nEndPos,i); sBuVm<H  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g#V3u=I8~  
fileSplitterFetch.start(); d0b--v/  
} b&g9A{t  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $ ;/Ny)"  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &Z+a (  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )>ed6A1  
nEndPos = " + nFileLength); [|2uu."$  
// fileSplitterFetch[nPos.length-1].start(); HRx%m1H  
BEM+FG  
Z;@F.r  
//等待子线程结束 Y.?|[x0Wh  
//int count = 0; T[=XGAJ  
//是否结束while循环 _9Kdcoh  
boolean breakWhile = false; a$MMp=p  
] t|KFk!)  
FeS6>/  
while(!bStop) -/aDq?<<  
{ j=)%~@  
write_nPos(); P Z-|W  
Utility.sleep(500); i4.s_@2Y  
breakWhile = true; S\Qh#y FT  
=VlO53Hy{  
/|y3M/;F  
for(int i=0;i<nStartPos.length;i++) }[PbA4l.g  
{ |,]#vcJP#b  
if(!fileSplitterFetch.bDownOver) gU/\'~HG  
{ "w`f>]YLA  
breakWhile = false; >]=1~ sF  
break; #UC4l]Ru A  
} fp9ksxb@m  
} -9{}rE  
if(breakWhile) y^zVb\"4  
break; R,A|"Q  
p]:~z|.Ba  
?x@BZe  
//count++; ~?aq=T  
//if(count>4) |rf\]3 F  
// siteStop(); gtz!T2%  
} 5/mW:G,&  
"HVwm>qEi  
pi5Al)0  
System.err.println("文件下载结束!"); SGH"m/ e  
} IgC)YIhd  
catch(Exception e){e.printStackTrace ();} 4(&00#Yxg2  
} T}P| uP  
,u( g#T  
N7Z&_$Bx  
//获得文件长度 1z~;c|  
public long getFileSize() @l&5 |Cia  
{ %yQ-~T@  
int nFileLength = -1; *ZGQ`#1.X6  
try{ x}1(okc  
URL url = new URL(siteInfoBean.getSSiteURL()); )xP]rOT  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~@z5Ld3xz  
httpConnection.setRequestProperty("User-Agent","NetFox"); t9m: E  
E[LXZh  
P-No;/!B#  
int responseCode=httpConnection.getResponseCode(); -z0,IYG }  
if(responseCode>=400) [j}%&$  
{ ~SZ0Yu:X  
processErrorCode(responseCode); &}w,bG$  
return -2; //-2 represent access is error Q=gVxS  
} {Y'DUt5j  
/Os)4yH\  
622mNY  
String sHeader; ,D3q8?j  
u!nt0hS  
"SyyOD )WA  
for(int i=1;;i++) nH% /  
{ g@nk0lQewj  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); + 7E6U*  
//Utility.log(in.readLine()); WLNkO^zb  
sHeader=httpConnection.getHeaderFieldKey(i); +zs;>'Sf  
if(sHeader!=null) SNff  
{ Y!o@"Ct  
if(sHeader.equals("Content-Length")) oLX6w  
{ ` M4; aN  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); MH"c=mL:  
break; ClVMZ  
} 43:~kCF[s  
} Aid{PGDk  
else ,i*^fpF`F"  
break; &.<{c `-  
} :!tQqy2  
} HK&F'\'}  
catch(IOException e){e.printStackTrace ();} =q[3/'2V$?  
catch(Exception e){e.printStackTrace ();} wC=IN   
K N0S$nW+  
-mX _I{BJ  
Utility.log(nFileLength); )l30~5u<J  
=q5A@!D  
 G!O D7:  
return nFileLength; w ^`n  
} |}q0 G~l  
d-N<VVcy\  
])~*)I~Y  
//保存下载信息(文件指针位置) 3QUe:8  
private void write_nPos() D9H|]W~   
{ <ze' o.c  
try{ )CdglPK  
output = new DataOutputStream(new FileOutputStream(tmpFile)); O:lD>A4{  
output.writeInt(nStartPos.length); 6/@ cP/  
for(int i=0;i<nStartPos.length;i++) +-ieaF  
{ rIge6A>I  
// output.writeLong(nPos); *i%!j/QDAP  
output.writeLong(fileSplitterFetch.nStartPos); 348Bu7':  
output.writeLong(fileSplitterFetch.nEndPos); do=VPqy  
} ]X?+]9Fr  
output.close(); |.(o4<nx.  
} |nD2k,S<?  
catch(IOException e){e.printStackTrace ();} {,s:vPoiA  
catch(Exception e){e.printStackTrace ();} `2S{.s  
} eIof{#  
VWfrcSZg6M  
mW8CqW\Q5  
//读取保存的下载信息(文件指针位置) RNX}Wlo-s  
private void read_nPos() :?RK>}4|F  
{ S~Q7>oNm  
try{ tinN$o Xy  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =/dW5qy;*+  
int nCount = input.readInt(); gdCU1D\  
nStartPos = new long[nCount]; {_[l,tdZ  
nEndPos = new long[nCount]; {b/AOR o  
for(int i=0;i<nStartPos.length;i++) Z"!C  
{ M"p$9t  
nStartPos = input.readLong(); `$@1NL7>  
nEndPos = input.readLong(); /~ V"v"7E  
} #C>pA<YJzK  
input.close(); 1uXtBk6  
} TF=S \ Q  
catch(IOException e){e.printStackTrace ();} JxD@y}ZYE  
catch(Exception e){e.printStackTrace ();} 'Fc&"(!||  
} $AsM 9D<BE  
3\D jV2t  
L9r 3jz  
private void processErrorCode(int nErrorCode) 7ky(g'  
{ 2s 6Vy  
System.err.println("Error Code : " + nErrorCode); S~6<'N&[  
} pd7FU~-  
>Q5 SJZ/  
]E=JUYf0  
//停止文件下载 oTx#e[8f{  
public void siteStop() o Y.JK  
{ N(1jm F  
bStop = true; L</"m[  
for(int i=0;i<nStartPos.length;i++) gXw\_ue<  
fileSplitterFetch.splitterStop(); AQ0L9?   
&S|laq H  
JHO9d:{-  
} *Z/B\nb  
} mup3ua]!  
//负责部分文件的抓取 h{PLyWH  
**FileSplitterFetch.java 8d$~wh  
*/ *$l8H[  
package NetFox; r2sog{R  
IRS^F;)  
1.>sG2*P  
import java.io.*; YKM(qh2  
import java.net.*; {L4^IKI  
>nr1|2  
{g )kT_  
public class FileSplitterFetch extends Thread {  g| r  
`DA=';>Y  
9L&AbmIr  
String sURL; //File URL gJF;yW 4  
long nStartPos; //File Snippet Start Position BO h  
long nEndPos; //File Snippet End Position ' GW@P  
int nThreadID; //Thread's ID #x%O0  
boolean bDownOver = false; //Downing is over {O^1WgGc[  
boolean bStop = false; //Stop identical 5 !NPqka}.  
FileAccessI fileAccessI = null; //File Access interface #bdJ]v.n  
5Cz:$-+  
~RMOEH.o  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Gu_s:cgB9F  
{ \h0e09& I  
this.sURL = sURL; A6UtpyS*'  
this.nStartPos = nStart; oFIs,[ Go  
this.nEndPos = nEnd; |x kixf4zz  
nThreadID = id; 0cS.|\ZTA  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vMC;5r6*d  
} -#Wc@\;  
K1+,y1c  
Viw{<VH=  
public void run() T%]: tDa  
{ z$YOV"N  
while(nStartPos < nEndPos && !bStop) RyM2CQg[  
{ igo7F@_,  
`zsKc 6%  
.#Sd|C]R7  
try{ 8;Pdd1GyUL  
URL url = new URL(sURL); _@RW7iP>  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c dGl[dQ/  
httpConnection.setRequestProperty("User-Agent","NetFox"); ]k KsGch  
String sProperty = "bytes="+nStartPos+"-"; mV4} -  
httpConnection.setRequestProperty("RANGE",sProperty); W%$p,^@S5  
Utility.log(sProperty); QR8F'7S  
d5],O48A  
Fvv6<E  
InputStream input = httpConnection.getInputStream(); XSD7~X/:  
//logResponseHead(httpConnection); 4a646jg)  
[%h^qJ  
i$NnHj|  
byte[] b = new byte[1024]; jgO{DNe(=  
int nRead; )O+9 v}2  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5GRN1Aov<  
{ @rJ#Dr  
nStartPos += fileAccessI.write(b,0,nRead); k~hL8ZT[  
//if(nThreadID == 1) > voUh;L  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z'fy9  
} zf S<X  
Cn{UzSKfs  
HL!-4kN <$  
Utility.log("Thread " + nThreadID + " is over!"); "xO`&a{  
bDownOver = true; VtmUK$k}I  
//nPos = fileAccessI.write (b,0,nRead); [ z&y]~  
} :?^(&3;  
catch(Exception e){e.printStackTrace ();} ~\kRW6  
} ^1nf|Xj [  
} WW_X:N~~e\  
#".{i+3E  
aY?}4Bx  
//打印回应的头信息 P$oa6`%l  
public void logResponseHead(HttpURLConnection con) oC?b]tzj  
{  #?,cYh+  
for(int i=1;;i++) ']rh0?  
{ :@3d  
String header=con.getHeaderFieldKey(i); "vJADQ4F  
if(header!=null) 9\n}!{@i  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8uu:e<PLv  
Utility.log(header+" : "+con.getHeaderField(header)); >\i{,F=U7  
else 0- #ct1-  
break; ~/.&Z`ls  
} Y}[r`}={  
} Fd 91Y  
3&zmy'b*:  
f2Slsl;  
public void splitterStop()   C[Fh^  
{ ew0 )  
bStop = true; U?rfE(!  
} 2Hd6  
8~I>t9Q+  
h?O-13v   
} :,u+[0-S  
F 4h EfO3  
9 o18VJR  
/* *%8us~w5/  
**FileAccess.java iVl"H@m/  
*//文件访问(定位,写) K~E]Fkw!;  
package NetFox; Ue\&  
import java.io.*; 2V0R|YUt  
- Z|1@s&  
H9nq.<;p  
public class FileAccessI implements Serializable{ mB :lp=c`  
(+U!# T]'D  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xpnnWHdaq  
RandomAccessFile oSavedFile; %NBD^g F  
long nPos; ;L)}blN.  
8[Qw8z5-  
xv ja  
public FileAccessI() throws IOException w_ Ls.K5"  
{ i a|F  
this("",0); urN&."c  
} 2<O hO ^  
BkJcT  
'2vlfQ@8a~  
public FileAccessI(String sName,long nPos) throws IOException &sllM  
{ _]4cY%s  
oSavedFile = new RandomAccessFile(sName,"rw"); WV6vM()#!C  
this.nPos = nPos; ewLr+8  
oSavedFile.seek(nPos); V?gQ`( ,  
} [ wROIvV  
emaNmpg  
F0yh7MItV  
public synchronized int write(byte[] b,int nStart,int nLen) J2R<'(  
{ Ug"B/UUFd  
int n = -1; l5MxJ>?4%B  
try{ +:t1PV;l  
oSavedFile.write(b,nStart,nLen); hb_Ia]b  
n = nLen; RWoiV10  
} x O)nS _I  
catch(IOException e) 7}#vANm  
{ Jk~T.p?tF  
e.printStackTrace (); " pH+YqJ$  
} eMF%!qUr  
`b2 I)xC#  
j4l7Tx  
return n; (I+-wki"e  
} x|Ei_hI-  
v|"{x&I.  
=:2V4H(F  
} B|%;(bM2C  
qle\c[UM5  
@fY!@xSf  
/* /yOd]N;$  
**SiteInfoBean.java pUPb+:^R  
*/ <ya3|ycnS  
package NetFox; *7R3EUUk  
kSJWQ  
fT@#S}t  
public class SiteInfoBean { k`&mHSk-  
ecF I"g  
o0/03O  
private String sSiteURL; //Site's URL Qh*|mW  
private String sFilePath; //Saved File's Path OUs2)H61  
private String sFileName; //Saved File's Name @#V{@@3$  
private int nSplitter; //Count of Splited Downloading File X=JSqO6V9  
OVd"'|&6_  
=thgNMDm"  
public SiteInfoBean() tQ)8HVKF  
{//nSplitter的缺省值为5 e"b F"L  
//default value of nSplitter is 5 -1{N#c/U  
this("","","",5); 5|Y4GQVz  
} p;p G@Vg  
}Orc;_)r  
k&**f_b  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |%tR#!&[:g  
{ n*;I2FV]  
sSiteURL= sURL; _#L IG2d  
sFilePath = sPath; 4@bL` L)  
sFileName = sName; F|PYDC  
this.nSplitter = nSpiltter; &o8\ $A  
& =frt3  
Q~]R#S  
} 9xSAWKr,l  
5~sJ$5<,  
'UB<;6wy  
public String getSSiteURL() eg}|%GG  
{ 1xx-}AIH#  
return sSiteURL; T.{I~_  
} tVe*J@i\$  
]y(#]Tw\  
"16==tLFE  
public void setSSiteURL(String value) sz)3 z  
{ F;z FKvn  
sSiteURL = value; D~1nh%x_  
} ,og@}gOMB  
bc&:v$EGy  
O,bj_CWx  
public String getSFilePath() 5!5P\o  
{ :hevBBP  
return sFilePath; }^QY<Cp|  
} W=|B3}C?  
c#l (~g$D+  
Lb];P"2e+  
public void setSFilePath(String value) IUZsLNW  
{ :n>h[{ o%  
sFilePath = value; !g}9xIL  
} !q/?t XM!  
R sujKh/  
7?A}q mv  
public String getSFileName() 3wr~P  
{ 8en85 pp8P  
return sFileName; I*24%z9  
} :H?p^d e  
Z|~<B4#c  
EatpORq  
public void setSFileName(String value) *m|]c4  
{ E]g KJVf9[  
sFileName = value; *+J&ebSTN  
} ,+q5e^P  
r67 3+  
plp).Gq  
public int getNSplitter() N),Zb^~nw  
{ Bz24U wcZ  
return nSplitter; 7{b|+0W  
} :Z/ ig%  
H\ NO4=  
Kj-`ru  
public void setNSplitter(int nCount) MjLyB^ M  
{ ?! kup  
nSplitter = nCount; ` "9Y.KU  
} !E*-\}[  
} (C. 1'<]  
#cApk  
3FS:]|oC  
/* ha(hG3C  
**Utility.java HFf| >&c&  
*/ ]])i"oew  
package NetFox; *M8 4Dry`y  
PCFm@S@Q  
#}A!Bk  
public class Utility { J"SAA0)@  
}b0qrr  
M r@M~ -  
public Utility() #7g~U m%p  
{ u{\`*dNx  
S4 tdW A  
zKI(yC  
} F 6SIhf.;  
xxedezNko  
//线程睡眠 kDm=Cjxv  
public static void sleep(int nSecond) z~X]v["d  
{ K7y}R%Q F  
try{ a#mdD:,cF  
Thread.sleep(nSecond); bb#w]!q  
} FS']3uJ/  
catch(Exception e) ,@2O_O`:  
{ 2 OGg`1XX  
e.printStackTrace (); aUJ&  
} .2u%;)S  
} QXF>xZ~  
'QkL%z0  
//日志 ,;{mH]"s  
public static void log(String sMsg) zZA I"\;W  
{ @@! R Iq!  
System.err.println(sMsg); 45_zO#  
} (apAUIE  
$YW z~^f  
&18} u~M  
public static void log(int sMsg) PAqziq.  
{ NW~n+uk5v  
System.err.println(sMsg); dz7*a {  
} ]5} =r  
} .kBAUkL:  
8^HMK$  
P+]39p{  
/* {E@@14]g  
**TestMethod.java b@,w/Uw[*  
*/ !ZB|GLpo6  
package NetFox; v1;`.PWD  
mjH8q&szf  
tFb49zbk  
public class TestMethod { ";xG[ne$Be  
J4x1qY)Y&v  
56L>tP  
public TestMethod() ?X=9@m  
{ ///xx/weblogic60b2_win.exe $3FFb#r  
try{ E|ZY2&J`4  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /TpM#hkq/2  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _~6AUwM  
SiteFileFetch fileFetch = new SiteFileFetch(bean); in%+)`'nH7  
fileFetch.start(); @P)GDB7A  
} (z"Cwa@e  
catch(Exception e){e.printStackTrace ();} >yT:eG  
=WN6Fj`  
JP[BSmhAV  
} CjIkRa@!x  
Prr<:q  
a-O9[?G/x  
public static void main(String[] args) \ar.(J  
{ koaH31Q  
new TestMethod(); 0xH$!?{b  
} +DVU"d  
}  #p\sw  
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
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