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
  • 8066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
/* 7e"(]NC84  
**SiteFileFetch.java ]H|1q uT  
*/ a[8_ O-   
package NetFox; @]h#T4z'  
import java.io.*; AH], >i3  
import java.net.*; *H RxC  
@*O(dw  
uL4@e  
public class SiteFileFetch extends Thread { 4.dMNqU  
jWW2&cBm\  
p8^^Pva/  
SiteInfoBean siteInfoBean = null; //文件信息Bean KXFa<^\o  
long[] nStartPos; //开始位置 !<2*B^   
long[] nEndPos; //结束位置 ':w6 {b  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 2h6F j&  
long nFileLength; //文件长度 hTn }AsfLY  
boolean bFirst = true; //是否第一次取文件 F<w/@ .&m  
boolean bStop = false; //停止标志 &,&oTd.  
File tmpFile; //文件下载的临时信息 a~~"2LE`  
DataOutputStream output; //输出到文件的输出流 /aJl0GL4!  
 D-4 PEf  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Dx[t?-  
public SiteFileFetch(SiteInfoBean bean) throws IOException 8`qw1dF  
{ %GS)9{T&  
siteInfoBean = bean; Urx gKTry  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); cY>;(x@  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Ec6{?\  
if(tmpFile.exists ()) %3VwCuE  
{ [* > @hx  
bFirst = false; RGtUKr'  
read_nPos(); T "G!H  
} r/O(EW#=8  
else tY :-13F  
{ 9AL\6 @<a*  
nStartPos = new long[bean.getNSplitter()]; )-a_,3x%j  
nEndPos = new long[bean.getNSplitter()]; C>;yW7*g"  
} r%'2a+}D  
5#f&WL*U@  
nw5#/5xw  
oaBfq8,;  
} 8a)EL*LH`  
+-~;?wA  
28BiuxVW  
public void run() ($W9 ?  
{ ccm <rZ7  
//获得文件长度 Ruk6+U  
//分割文件 SqTm/ t  
//实例FileSplitterFetch 3nK'yC  
//启动FileSplitterFetch线程 V`WfJ>{;Z  
//等待子线程返回 y~S[0]y>  
try{ ypd  
if(bFirst) up2%QbN(  
{ ^LC5orO  
nFileLength = getFileSize(); .(1$Q6yG  
if(nFileLength == -1) {2:H`|x  
{ %r!#  
System.err.println("File Length is not known!"); H[Pb Wy:  
} puqH%m+u  
else if(nFileLength == -2) >LU*F|F]B  
{ E>6zwp  
System.err.println("File is not access!"); 4 |5ekwk  
} kh,M'XbTo  
else w6 "LHy[  
{ MB |(,{S  
for(int i=0;i<nStartPos.length;i++) Ol%*3To  
{ *j*jA/  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); q-8  GD7  
} nf G:4k,  
for(int i=0;i<nEndPos.length-1;i++) 9wb$_j]F`#  
{ @g=A\2  
nEndPos = nStartPos[i+1]; ^3yjE/Wi"  
} n'h )(^  
nEndPos[nEndPos.length-1] = nFileLength; w\2[dd  
} r 2H'r ,N  
} rP\ 7C+  
<0LB]zDWe6  
wFd*6%  
//启动子线程 -=sxbs.aA  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \A~  '&  
for(int i=0;i<nStartPos.length;i++) ~V|!\CB  
{ <s7{6n')  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g<dCUIbcQ  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~!nd'{{9  
nStartPos,nEndPos,i); #U_u~7?H$  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z~Pmh%b  
fileSplitterFetch.start(); ``E;!r="v  
} fVN}7PH7+  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $cy:G  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /pge7P  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,/ig8~u'c  
nEndPos = " + nFileLength); AeJM[fCMa  
// fileSplitterFetch[nPos.length-1].start(); f%}+.e D  
jN<]yhqf  
QNtr=  
//等待子线程结束 bn(Scl#@K  
//int count = 0; ?rK%;GTo  
//是否结束while循环 =J'?>-B  
boolean breakWhile = false; p.\KmEx  
C1do]1VH  
.6;B3  
while(!bStop) GB+d0 S4  
{ &T|-K\*  
write_nPos(); z g j35  
Utility.sleep(500); Yptsq@s  
breakWhile = true; LK%B6-;~-  
=Ffq =<  
G_<[sMC8  
for(int i=0;i<nStartPos.length;i++) ~^C7(g )  
{ Kk(ucO  
if(!fileSplitterFetch.bDownOver) cU6#^PFu  
{ E0h p%:  
breakWhile = false; s*X\%!l9  
break; Iw:("A&~  
} v}Nx*%  
} $^XPk#$m  
if(breakWhile) ["IJ h  
break; '_<`dzz  
9]w0zUOL6  
^U?(g0<"  
//count++; 9M=K@a  
//if(count>4) WuQYEbap  
// siteStop(); 8{l=`y"nB  
} .0-m=3mp2  
ykeUS zz2  
? 7EVmF  
System.err.println("文件下载结束!"); d&u/7rm  
} 4a|Fx  
catch(Exception e){e.printStackTrace ();} '9dtIW6E  
} N9PM.nbd%  
[-gKkOT8E  
<khAc1"  
//获得文件长度 UmE{>5Pt  
public long getFileSize() \|t0~sRwh  
{ y~=hM   
int nFileLength = -1; >PVi 3S  
try{ @[RY8~  
URL url = new URL(siteInfoBean.getSSiteURL()); 614/wI8(  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9"RfL7{  
httpConnection.setRequestProperty("User-Agent","NetFox"); 6V?RES;X  
XOwMT,=Z)  
"poTM[]tZ7  
int responseCode=httpConnection.getResponseCode(); xwxjj  
if(responseCode>=400) z{jAt6@7  
{ D5b _m|7%  
processErrorCode(responseCode); kZ}u  
return -2; //-2 represent access is error PPO<{  
} g DG m32  
NGs9Jke2  
TjK5UML  
String sHeader; 90ag!   
jq)|7_N  
}_22 wjm~  
for(int i=1;;i++) Ve1] ECk  
{ IpXhb[UZ?  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); EM/+1 _u  
//Utility.log(in.readLine()); z{0;%E  
sHeader=httpConnection.getHeaderFieldKey(i); t g*[%Jf^  
if(sHeader!=null) \>`$x:  
{ K-C,+eI  
if(sHeader.equals("Content-Length")) g0OS<,:  
{ ,b(S=r  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,O)\,tg  
break; ZcRm5Du~:  
} ;_a oM&  
} F\rSYjMyk  
else 7YjucPH#  
break; [s{:}ZuKc  
} f4T0Y["QA  
} .6F3;bg R7  
catch(IOException e){e.printStackTrace ();} I?g__u=n~  
catch(Exception e){e.printStackTrace ();} h}>/Z3*  
Kn$1W=B1.  
] *VF Ws  
Utility.log(nFileLength); da'E"HN@G~  
X/Rx]}[   
5)5bt q)[  
return nFileLength; M9g\/]Io;  
} |I5?5 J\  
s)8M? |[`I  
%,cFX[D/)  
//保存下载信息(文件指针位置) 5a!e%jj  
private void write_nPos() PB67 ?d~  
{ yN<fmi};c  
try{ VFSn!o:C  
output = new DataOutputStream(new FileOutputStream(tmpFile)); J_E(^+  
output.writeInt(nStartPos.length); f}Tr$r  
for(int i=0;i<nStartPos.length;i++) xt,L* B  
{ ~*c=  
// output.writeLong(nPos); ^p zxwt  
output.writeLong(fileSplitterFetch.nStartPos); 0P40K  
output.writeLong(fileSplitterFetch.nEndPos); TK/'=8  
} W.D3$  
output.close(); %N>NOk)  
} { DQ E7kI  
catch(IOException e){e.printStackTrace ();} ~o'#AP#N~  
catch(Exception e){e.printStackTrace ();} 9Pp|d"6]y  
} M6*{#Y?  
X7d.Ie  
fP1OH&Ar  
//读取保存的下载信息(文件指针位置) s8d}HI  
private void read_nPos() ?EQ^n3U$  
{ nCMa$+  
try{ z12But\<  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); X5|/s::u  
int nCount = input.readInt(); wy- C~b'Qd  
nStartPos = new long[nCount]; qZsddll  
nEndPos = new long[nCount]; >[fVl 8G_0  
for(int i=0;i<nStartPos.length;i++) G0 /vn9&  
{ HU[nN*  
nStartPos = input.readLong(); {Y:ZY+  
nEndPos = input.readLong(); mhLRi\[c )  
} Rw\C0'  
input.close(); _+ 04M)q0  
} ?wf+{x-dPP  
catch(IOException e){e.printStackTrace ();} _6UAeZ*M  
catch(Exception e){e.printStackTrace ();} 5Vo}G %g  
} ;;'a--'"  
t?nc0;Q9,@  
m_"p$m;  
private void processErrorCode(int nErrorCode) 1uS-Tx  
{ )Ct*G= N  
System.err.println("Error Code : " + nErrorCode); G P[r^Z  
} (5q%0|RzRs  
RYZE*lWUh  
soq".+Q  
//停止文件下载 qm}>J^hnB#  
public void siteStop() +Sd,l>8\  
{ ? TT8|Os  
bStop = true; yb4tJu$  
for(int i=0;i<nStartPos.length;i++) IiK(^:~%  
fileSplitterFetch.splitterStop(); #>:(#^Uu  
yLz,V}  
)Bn>/-  
} z34>,0  
} ^~6]0$yJ  
//负责部分文件的抓取 #xP!!.DF(  
**FileSplitterFetch.java !b]2q%XM  
*/ "?SOBA!vy  
package NetFox; jfY{z=*]u  
q|u8CX  
/"Yx@n  
import java.io.*; TA0D{  
import java.net.*; x 1BOW  
GX@W"y  
N8XC~Dh{  
public class FileSplitterFetch extends Thread { J,1osG<6x  
&6t3SZV  
a}Fk x  
String sURL; //File URL -N7xO)  
long nStartPos; //File Snippet Start Position k?HrD"k"  
long nEndPos; //File Snippet End Position f' '{.L  
int nThreadID; //Thread's ID mUt,Z^ l`  
boolean bDownOver = false; //Downing is over -H4+ur JJ  
boolean bStop = false; //Stop identical =\Vu=I  
FileAccessI fileAccessI = null; //File Access interface kWs+2j  
^V: "zzn&  
?cO8'4 bq  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException L8dU (P  
{ l7'{OB L  
this.sURL = sURL; o3F|#op  
this.nStartPos = nStart; ``|gcG  
this.nEndPos = nEnd; d=?Mj]  
nThreadID = id; 3Rd`Ysp  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Jh\: X<q  
} j6e}7  
g8,?S6\nMz  
^S#\O>GHP  
public void run() ~#x :z ^U  
{ NuD[-;N]  
while(nStartPos < nEndPos && !bStop) "brRME3  
{ }. xrJ52Tz  
SH vaV[C  
;vJ\]T ml  
try{ _V& !4Zd9:  
URL url = new URL(sURL); Ns2,hQFc  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `c'   
httpConnection.setRequestProperty("User-Agent","NetFox"); $U>/i@D  
String sProperty = "bytes="+nStartPos+"-"; v]:+` dV  
httpConnection.setRequestProperty("RANGE",sProperty); ;+i'0$;*w  
Utility.log(sProperty); DikdC5>O>m  
TX23D)CX  
xJ~ gT  
InputStream input = httpConnection.getInputStream(); `S\zqF<  
//logResponseHead(httpConnection); ^Ti_<<X  
-^iUVO`z  
$Ns,ts(ng  
byte[] b = new byte[1024]; J%\- 1  
int nRead; AfRW=&xdT  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _%'L@[ H  
{ 2~!R*i  
nStartPos += fileAccessI.write(b,0,nRead); R <;OEN  
//if(nThreadID == 1) x6^l6N  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2e9jo,i  
} Zk=*7?!!  
<)O >MI' 4  
C,A!tj7@  
Utility.log("Thread " + nThreadID + " is over!"); > -y&$1  
bDownOver = true; T- |9o|~z  
//nPos = fileAccessI.write (b,0,nRead); MzQ\rg_B7  
} #wenX$UTh3  
catch(Exception e){e.printStackTrace ();} UvxSMD:A  
} qKdS7SoS  
} N0Efw$u  
Vi|7%!j<  
HDmx@E.@  
//打印回应的头信息 M18qa,fK{  
public void logResponseHead(HttpURLConnection con) +Edzjf~Tt  
{ 9u,8q:I.?  
for(int i=1;;i++) G'f9N^w  
{ <4bz/^  
String header=con.getHeaderFieldKey(i); j8GY`f#  
if(header!=null) E6Q]A~  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -<qxO  
Utility.log(header+" : "+con.getHeaderField(header)); :dP~.ZY7  
else SY-ez 91  
break; i;o}o *=  
} $Y6I_U  
} {L@+(I  
0K<x=-cCB  
,~4H{{<j  
public void splitterStop() X^}A*4j  
{ Rj[ hhSx 2  
bStop = true; TUh&d5a9H  
} ]^=|Zd-  
qib 7Z]j  
KRYcCn  
}  fb\DiKsW  
ugYw <  
Ji;SY{~kv  
/* ]3*P:$Rq  
**FileAccess.java ha*X6R  
*//文件访问(定位,写) ~>V-*NT8  
package NetFox; #s"851e  
import java.io.*; q|5Q?t:,r  
5|ic3  
N.Dhu~V  
public class FileAccessI implements Serializable{ *E:x E/M!2  
qmZ2d!)o  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 o+nG3kRD  
RandomAccessFile oSavedFile; GCT@o!  
long nPos; D+Cm<ZT~  
aG%kmS&fv  
5m4DS:&  
public FileAccessI() throws IOException !(Krf  
{ b"``D ?  
this("",0); KP3n^ $~  
} x97L6!  
Lf. 1>s  
JqEW= 5  
public FileAccessI(String sName,long nPos) throws IOException u~W{RHClW  
{ OifvUTl9b  
oSavedFile = new RandomAccessFile(sName,"rw"); mN;+TN'?{  
this.nPos = nPos; iq?l#}]  
oSavedFile.seek(nPos); eNRs&^  
} !X|k"km"  
{<2>6 _z  
hd B |#t  
public synchronized int write(byte[] b,int nStart,int nLen) #,L~w  
{ 7^$)VBQ/  
int n = -1; XS?gn.o\  
try{ "PMQyzl  
oSavedFile.write(b,nStart,nLen); +t98 @  
n = nLen; DkgUvn/S  
} mEFw|M{  
catch(IOException e) Yd:Q`#7A  
{ f1mHN7hxW  
e.printStackTrace (); !VwmPAMr#v  
} y4@gGC=  
$Pxb1E  
d?A}qA[(  
return n; -v+&pG?m  
} +2RNZEc  
fW?sYC'  
 ~,"N[Q  
} B8T\s)fxnX  
?}}qu'N:N  
2j&v;dmh<  
/* 8d!GZgC8R  
**SiteInfoBean.java Qzqc .T  
*/ a+`D'?z  
package NetFox;  PWH^=K  
=E(#YCx  
Z) Wnow  
public class SiteInfoBean { `0bP0^w  
]f8L:=c  
PU1,DU  
private String sSiteURL; //Site's URL h[kU<mU"T  
private String sFilePath; //Saved File's Path x5}lgyt  
private String sFileName; //Saved File's Name )I`if(fG  
private int nSplitter; //Count of Splited Downloading File rn8cdM N  
xzsdG?P  
IA4N@ijRxh  
public SiteInfoBean() .2W"w)$nuq  
{//nSplitter的缺省值为5 mT @ nn,  
//default value of nSplitter is 5 n[,XU|2  
this("","","",5); |a-fE]{7  
} 6)qp*P$L  
rh!;|xB|+  
7" 4z+w  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -)v@jlg02  
{ +5!&E7bcd  
sSiteURL= sURL; {u"8[@@./  
sFilePath = sPath; :@eHX&  
sFileName = sName; ST1'\Eo  
this.nSplitter = nSpiltter; s$w;q\1z  
Vi?q>:E:  
z.36;yT/  
} X^s2BW  
o(!@7Lqq  
a~PK pw2%  
public String getSSiteURL() ;f1qLI  
{ xb:&(6\F  
return sSiteURL; }^xE|~p  
} X(@uwX$m  
-MBV $:_R  
D`[Khsf  
public void setSSiteURL(String value) d$t40+v  
{ s@8w-]"  
sSiteURL = value; -TO\'^][X  
} w_hHfZ9E  
ALc`t(..}A  
a0=WfeT  
public String getSFilePath() T 2F6)e  
{ tyh@ ^7  
return sFilePath; %eg+F  
} H,QTYXi "  
y7/F _{  
j$Ab>}g]  
public void setSFilePath(String value) @n -r-Q  
{ )5_jmW`n  
sFilePath = value; S<`I Jpkv  
} !cSq+eD  
- +> 1r  
:o46rBs  
public String getSFileName() q?):oJ  
{ KC`q#&dt  
return sFileName; */^QH@P  
} cPDQ1qre!  
`R"~v/x  
jYRP8 Yi  
public void setSFileName(String value) :9|\Z|S(I  
{ _oG&OJ@  
sFileName = value; bq>_qpr  
} b2,!g }I  
g[H',)A)  
nKoiG*PI  
public int getNSplitter() |~!U4D\  
{ t]aea*B  
return nSplitter; qIIJ4n  
} 0@I S  
H+E$:)gN  
\C,p WW  
public void setNSplitter(int nCount) _P?s'HH  
{ vi.w8 >CE  
nSplitter = nCount; |`TgX@,#9  
} En{`@JsM  
} 1r Ky@9   
M_g ?<rK  
@$9'@")  
/* F$BbYf2i  
**Utility.java V#REjsf,t-  
*/ #@HF<'H}mu  
package NetFox; $+p?Y)h .  
LbEM^ D  
UT0){%2@  
public class Utility { [NMVoBvG  
u .f= te  
21hv%CF\9  
public Utility() ^XbU~3(  
{ }}v9 `F  
6AG`&'"  
1#IlWEg  
} I/Jb!R ~  
|a1{ve[  
//线程睡眠 ~5FW [_  
public static void sleep(int nSecond) I[)%,jd  
{ mKr h[nA  
try{ h2ytS^  
Thread.sleep(nSecond); 7f rTTSZ  
} %\]* OZ7  
catch(Exception e) ) e5 @  
{ wLK07e(  
e.printStackTrace (); (e(:P~Ry  
} <-D/O$q  
} ^8.]d~j  
YIw1  
//日志 ~ab:/!Z  
public static void log(String sMsg) T,aW8|  
{ $9Hcdbdm  
System.err.println(sMsg); fhL,aCS=  
} Pj}6 6.  
VD_$$Gn*q  
-py@DzK  
public static void log(int sMsg) FEVEp  
{ PDs@?nz,  
System.err.println(sMsg); $Y69@s%f  
} ;)N>t\v  
} wF((  
(=7Cs  
9$2/MT't  
/* 0 a80 LAK  
**TestMethod.java th;{V%:LW  
*/ &=VDASEu  
package NetFox; ^R:cd8+?%  
"[y-+)WTG  
g+J-Zg6  
public class TestMethod { 0u\GO;  
y;s`P .  
~\J}Kqg  
public TestMethod() tH-C8Qxy  
{ ///xx/weblogic60b2_win.exe ,^uEYT}j  
try{ RzWXKBI\E]  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); w.[ "p9tc  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;q*e=[_DF  
SiteFileFetch fileFetch = new SiteFileFetch(bean); M5 <@~V/[  
fileFetch.start(); : |>Gc39`t  
} +E{|63~q  
catch(Exception e){e.printStackTrace ();} s&RVJX>Rt  
6Vz9?puD  
\[y`'OD~  
} PYGRsrcFd#  
)jt #=9ZQ  
A!h`]%0B  
public static void main(String[] args) D8$G`~hD  
{ @nux9MX<9  
new TestMethod(); v%q0OX>9X"  
} <yd{tD$A*  
} 3\XU_Xs(]  
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