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
  • 7680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
/* [ &R-YQ@  
**SiteFileFetch.java WWq)Cw R  
*/ 0W]Wu[k  
package NetFox; d [K56wbpx  
import java.io.*; 9[$g;}w  
import java.net.*; Kw925@W  
f9OVylm  
VbA#D4;  
public class SiteFileFetch extends Thread { 9{ciD "!&V  
Ep?a1&b  
,'82;oP4  
SiteInfoBean siteInfoBean = null; //文件信息Bean Ct"h.rD]  
long[] nStartPos; //开始位置 L>pP3[~DV  
long[] nEndPos; //结束位置 6>bKlYl&9  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 0g`WRe  
long nFileLength; //文件长度 n6ud;jN|  
boolean bFirst = true; //是否第一次取文件 ,n&Dg58K  
boolean bStop = false; //停止标志 G 7zfyw}W  
File tmpFile; //文件下载的临时信息 C"hc.A&4  
DataOutputStream output; //输出到文件的输出流 WY<ip<  
OEZXV ;F  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) T[ky7\  
public SiteFileFetch(SiteInfoBean bean) throws IOException /mqEc9sq,  
{ gEPCXf  
siteInfoBean = bean; uOm fpgO  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); c;(}Ih(#  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ;k!Ej-(  
if(tmpFile.exists ()) rQ~%SUM7  
{ ^#g GA_H  
bFirst = false; \n+`~< i  
read_nPos(); B>9D@fmzs  
} 4my8 p Fk  
else FC vR  
{ Ur5X~a\y  
nStartPos = new long[bean.getNSplitter()]; J,P7k$t2vv  
nEndPos = new long[bean.getNSplitter()]; pMs%`j#T  
} :/ "q NPJ  
,uDB ]  
:vV?Yv%P)n  
bpKb<c  
} !f_Kq$.{  
]lm9D@HMC  
z2nDD6N  
public void run() ?i9LqHL  
{ zb:p,T@5  
//获得文件长度 g($y4~#  
//分割文件 N2q'$o  
//实例FileSplitterFetch nA%-<  
//启动FileSplitterFetch线程 MPM_/dn-  
//等待子线程返回 UW)k]@L  
try{ |A5]hL   
if(bFirst) gqG l>=.m  
{ NV*t  
nFileLength = getFileSize(); ,4EE9 ?J  
if(nFileLength == -1) #[Ns\%Ri0  
{ ZTHr jW1  
System.err.println("File Length is not known!"); ?4gYUEM#  
} U'Vz   
else if(nFileLength == -2) 5k<HO_]  
{ ~e'FPVDn  
System.err.println("File is not access!"); <3ovCqa  
} YzEa?F*$  
else $yc&f(Tv  
{ ^\Jg {9a  
for(int i=0;i<nStartPos.length;i++) h9SS o0]F  
{ z[CCgs&vqe  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); `[CXxp  
} C2DNyMu  
for(int i=0;i<nEndPos.length-1;i++) H-0deJ[>  
{ cBc6*%ZD  
nEndPos = nStartPos[i+1]; !k%Vw1 8  
} hM+nA::w  
nEndPos[nEndPos.length-1] = nFileLength; <R_3; 5J%  
} H |75,!<  
} u9k##a4.E  
QeU>%qKT  
BA L!6  
//启动子线程 W\FKA vS  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &5C%5C~ch  
for(int i=0;i<nStartPos.length;i++) g[:5@fI#*  
{ nD E5A  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T>W(Caelq  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tAYu|\]  
nStartPos,nEndPos,i); ^VoQGP/cl  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ml0d^l}'  
fileSplitterFetch.start(); BKVvu}V(o  
} 9u"im+=:  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @Q TG  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z`< +8e  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _mFb+8C  
nEndPos = " + nFileLength);  21w<8:Vg  
// fileSplitterFetch[nPos.length-1].start(); e|]g ?!  
_khQ  
7|"11^q  
//等待子线程结束 B/pNM81(  
//int count = 0; D`,@EW].  
//是否结束while循环 `(Ei-$ >U&  
boolean breakWhile = false; 6n;ewl}  
 @(Q4  
42Ql^ka  
while(!bStop) $mp7IZE|  
{ sm\/wlbE  
write_nPos(); */?L_\7  
Utility.sleep(500); x{RTI#a.  
breakWhile = true; b!_l(2  
dp_J*8  
WET $H,  
for(int i=0;i<nStartPos.length;i++) 5%,n[qj4IT  
{ .DCp)&m l;  
if(!fileSplitterFetch.bDownOver) l,sYYU+iY  
{ $F\&?B1.  
breakWhile = false; QAcvv 0Hv  
break; #`}g?6VHo  
} a?Q~C<k  
} | ql!@M(p  
if(breakWhile) 9Q].cDe[  
break; YQe @C  
LOe!qt\&  
Og-M nx3  
//count++; `4Nc(aUr  
//if(count>4) `4l>%S8y:  
// siteStop(); M,y='*\M  
} ]FQ4v.7  
E2%7v  
9-pd{Z~l  
System.err.println("文件下载结束!"); pmHd1 Wub  
} QIo|t!7F  
catch(Exception e){e.printStackTrace ();} h7(twct  
} t1IC0'o-  
2c9@n9Vx3a  
{zmo7~=  
//获得文件长度 ed*=p l3.  
public long getFileSize() f{^n<\Jh  
{ ( |O;Ci  
int nFileLength = -1; _VR4 |)1g  
try{ x{Gih 1  
URL url = new URL(siteInfoBean.getSSiteURL()); 'KyT]OObS  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |oO0%#1H  
httpConnection.setRequestProperty("User-Agent","NetFox"); bu@Pxz%_  
Wpj.G  
nc@ul')  
int responseCode=httpConnection.getResponseCode(); ZFrK'BvbR  
if(responseCode>=400) yf_<o   
{ '_(oa<g  
processErrorCode(responseCode); F)v+.5T1  
return -2; //-2 represent access is error g/V C$I!'  
} cDE?Xo'!  
'!IX;OSjH  
T /[)U  
String sHeader; B(b[Dbb  
F KL}6W:  
M(oW;^B  
for(int i=1;;i++) <2|x]b 8  
{ 5Ko "-  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); REFisH-  
//Utility.log(in.readLine()); ls #O0  
sHeader=httpConnection.getHeaderFieldKey(i); (Grj_p6O  
if(sHeader!=null) V@cRJ3ZF  
{ mb\vHu*53  
if(sHeader.equals("Content-Length")) * Q51'?y  
{ NP%ll e,l  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I+u=H2][2  
break; [-Q"A 6!Zd  
} Mzxz-cE  
} S2j7(T;~YB  
else 0r+-}5aSl5  
break; =X+DC&]%!  
} :~6%nFo  
} AZ!G-73  
catch(IOException e){e.printStackTrace ();} \k;raQR4t*  
catch(Exception e){e.printStackTrace ();} !K`;fp!  
Xb6@;G"  
vs6`oW"{#  
Utility.log(nFileLength); EXb{/4  
%y8w9aGt  
zU1rjhv+  
return nFileLength; QHtpCNTVb  
} -pX/Tt6  
xB9^DURr\  
7g(rJGjtg  
//保存下载信息(文件指针位置) Hi.JL  
private void write_nPos() >@]E1Qfe  
{ 5<d Y,FvX  
try{ P=u)Q _  
output = new DataOutputStream(new FileOutputStream(tmpFile)); nc$?tC9V  
output.writeInt(nStartPos.length); |L]dJ<  
for(int i=0;i<nStartPos.length;i++) lzuPE,h  
{ vuw1ycy)  
// output.writeLong(nPos); ?\^u},HnE|  
output.writeLong(fileSplitterFetch.nStartPos); |vEfE{  
output.writeLong(fileSplitterFetch.nEndPos); p aMw88*u  
} ed\,FWR  
output.close(); '7_'s1  
} Y]P $|JW):  
catch(IOException e){e.printStackTrace ();} y>wr $  
catch(Exception e){e.printStackTrace ();} D8Ni=.ALL  
} s,` n=#  
%>24.i"l  
fI"`[cA"]  
//读取保存的下载信息(文件指针位置) CGv(dE,G&]  
private void read_nPos() vLpE|QZs  
{ ~(hmiNa;  
try{ D(Xv shQ  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |mci-ZT  
int nCount = input.readInt(); 5|H?L@_9  
nStartPos = new long[nCount]; 5HOhk"  
nEndPos = new long[nCount]; ;5 IS58L  
for(int i=0;i<nStartPos.length;i++) Of:e6N  
{ #2u-L~n  
nStartPos = input.readLong(); Zvr(c|Q  
nEndPos = input.readLong(); Yz%=  
} A.z~wu%(  
input.close(); [~jh Ov^  
} RsrZ1dhPvV  
catch(IOException e){e.printStackTrace ();} ?%;uR#4  
catch(Exception e){e.printStackTrace ();} 3zh'5qQ  
} kTFN.kQx@  
p&ow\A O  
P#Eqe O  
private void processErrorCode(int nErrorCode) `o:)PTQNg  
{ $g 1p!  
System.err.println("Error Code : " + nErrorCode);  JTz1M~  
} 7a@V2cr@  
,ew<T{PL  
uy`U1>  
//停止文件下载 '# (lq5 c  
public void siteStop() 's&Vg09D,  
{ '*)!&4f  
bStop = true; U?>zq!C&R  
for(int i=0;i<nStartPos.length;i++) ;#f%vs>Y7i  
fileSplitterFetch.splitterStop(); faMUd#o&  
y{jv-&!xB  
)03.6 Pvs  
} j- A S {w  
} b*p,s9k7  
//负责部分文件的抓取 Qt@~y'O  
**FileSplitterFetch.java tgrQ$Yjk  
*/ lXB_HDY  
package NetFox; Tri.>@-u  
EH,uX{`e  
/~AwX8X  
import java.io.*; IM +Dm  
import java.net.*; <GoE2a4Va  
n.7 $*9)#  
Q jQJ "  
public class FileSplitterFetch extends Thread { {]Lc]4J  
&4{%3w_/  
.|iUDp6vz  
String sURL; //File URL T-<^mX[}  
long nStartPos; //File Snippet Start Position ;$|+H"g|  
long nEndPos; //File Snippet End Position Z;%qpsq  
int nThreadID; //Thread's ID yM#W,@  
boolean bDownOver = false; //Downing is over  ym${4  
boolean bStop = false; //Stop identical w#JF7;  
FileAccessI fileAccessI = null; //File Access interface TFM}P  
"KFCA9u-  
RmzK?muk  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException MN1|k  
{ Nwu#,f=X  
this.sURL = sURL; nLQ X? :  
this.nStartPos = nStart; uO":\<1#  
this.nEndPos = nEnd; 4|XE f,  
nThreadID = id; hs/nM"V  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +x+H(of.  
} -Mv`|odY/  
x80~j(uVf  
B}?/oZW 4  
public void run() &/7GhZRt  
{ F htf4  
while(nStartPos < nEndPos && !bStop) 9_TZ;e  
{ }[75`pC~O  
e7hPIG  
<BO|.(ys  
try{ ;dB=/U>3U  
URL url = new URL(sURL); - iJ[9O  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xQmk2S` y  
httpConnection.setRequestProperty("User-Agent","NetFox"); G`)I _uO  
String sProperty = "bytes="+nStartPos+"-"; [&Qrk8EN  
httpConnection.setRequestProperty("RANGE",sProperty); (Ojg~P4;&  
Utility.log(sProperty); 8fDnDA.e  
Dnd  
s"sX# l[J  
InputStream input = httpConnection.getInputStream(); y:v0& 9L  
//logResponseHead(httpConnection); #z5'5|3  
M8g=t[\  
*XNvb ^<  
byte[] b = new byte[1024]; G LE`ba  
int nRead; bAW;2 NB  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^U`[P@T  
{ 0<^K0>lm p  
nStartPos += fileAccessI.write(b,0,nRead); "ENgu/A!  
//if(nThreadID == 1) Ay2|@1e  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *1elUI2Rg  
} Duz}e80  
>iG`  
2+Fq'!  
Utility.log("Thread " + nThreadID + " is over!"); >\@6i s  
bDownOver = true; gbI0?G6XN/  
//nPos = fileAccessI.write (b,0,nRead); C6/,-?%)  
} Fa>Y]Y0r  
catch(Exception e){e.printStackTrace ();} @c{Z?>dUc#  
} 31bKgU{  
} "@Te!.~A.  
6aj)Fe'2  
#G]s.by('  
//打印回应的头信息 O:u^jcXA  
public void logResponseHead(HttpURLConnection con) <89 js87  
{ \x|(`;{  
for(int i=1;;i++) {yfG_J  
{ kvo741RO6  
String header=con.getHeaderFieldKey(i); kmP0gT{Sj  
if(header!=null) 0TVO'$Gvi  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5))?,YkrrI  
Utility.log(header+" : "+con.getHeaderField(header)); |5Z@7  
else ff{ESFtD  
break; `T~M:\^D  
} 6}<PBl%qe  
} ['sIR+c%'O  
9g 2x+@5T^  
Z9!goI  
public void splitterStop() y`\/eX  
{ .oSKSld  
bStop = true; @NV$!FB<  
} S'?XI@t[  
(-~tb-  
|1t30_ /gS  
} Nzr zLK  
qdcCX:Z<  
d/* [t!   
/* w0 "h,{  
**FileAccess.java m&; t;&#  
*//文件访问(定位,写) `@`Q"J  
package NetFox; |7f}icXKur  
import java.io.*; "e(OO/EZS  
ss-Be  
0gt/JI($  
public class FileAccessI implements Serializable{ H:0-.a^ZS  
8LiRZ"  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 43 |zjE  
RandomAccessFile oSavedFile; Oj<2_u  
long nPos; Ujw ^j  
\DfvNeF  
Gz6FwU8L  
public FileAccessI() throws IOException ){gOb  
{ (hmasy6hM  
this("",0); &5zUk++  
} v 7Pv&|  
S Xgpj  
<QszmE  
public FileAccessI(String sName,long nPos) throws IOException fHwh6|  
{ ;9;.!4g/T  
oSavedFile = new RandomAccessFile(sName,"rw"); [KCh,'&  
this.nPos = nPos; (:@qn+ a  
oSavedFile.seek(nPos); EJL45R>  
} iVmf/N@A|  
f2yc]I<lr~  
b7"pm)6  
public synchronized int write(byte[] b,int nStart,int nLen) SHh g&~B  
{ A #ZaXu/:X  
int n = -1; "\> <UJ  
try{ )Hw;{5p@  
oSavedFile.write(b,nStart,nLen); hBN!!a|l  
n = nLen; Iy e  
} `~*qjA  
catch(IOException e) ?VReKv1\  
{ f^0vkWI2  
e.printStackTrace (); }3N8EmS  
} lOZ.{0{f,  
A0&~U0*(~  
 V+(  
return n; )_+#yaC  
} c) 1m4SB@  
'+-R 7#  
yqCy`TK8  
} y.mojx%?a  
%f, 9  
cZ o]*Gv.  
/* a1om8!C  
**SiteInfoBean.java R=8!]Oi6  
*/ VsUEp_I  
package NetFox; E{lq@it32p  
n>!E ]  
EStHl(DUPq  
public class SiteInfoBean { f~"3#MaV  
(|bht0  
zW+Y{^hf  
private String sSiteURL; //Site's URL J$'T2@H#  
private String sFilePath; //Saved File's Path AKL~F|t  
private String sFileName; //Saved File's Name 7tfFRUw  
private int nSplitter; //Count of Splited Downloading File pk"JcUzR  
@*_#zU#g  
h=)Im )  
public SiteInfoBean() 0MPsF{Xw[  
{//nSplitter的缺省值为5 ]=h Ts%]w  
//default value of nSplitter is 5 A6#ob  
this("","","",5); }V9146  
} +Mg^u-(A  
<pi q?:ac  
l65'EO|  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]4hXK!^Uu  
{ ,[~Ydth  
sSiteURL= sURL; to,=Q8 )0  
sFilePath = sPath; G::6?+S  
sFileName = sName; g]jtVQH']  
this.nSplitter = nSpiltter; kqHh@]Z0'  
Zwq uS9  
8l)l9;4 6  
} $aGK8%.O  
5%G++oLXf  
$\a;?>WA"  
public String getSSiteURL() Bt.W_p  
{ tD>m%1'&  
return sSiteURL; q9Fc0(&Vf  
} ")Bf^DV  
}rGDM  
sU{+.k{  
public void setSSiteURL(String value) FeCQGT  
{ K$(U>D|  
sSiteURL = value; WgY\m&  
} /:%^Vh3XF  
q^12Rj;H  
tkJ/ h<  
public String getSFilePath() :  l]>nF4  
{ ?g<*1N?:  
return sFilePath; '#q"u y  
} EB\z:n5  
WqTW@-}ID  
Q~*A`h#  
public void setSFilePath(String value) ((X"D/F]  
{ MTqbQ69v  
sFilePath = value; %DRDe  
} w7%N=hL1   
s/A]&! `  
Q/0}AQO  
public String getSFileName() 8uCd|dJ  
{ s]B^Sz=  
return sFileName; 9|#h )*  
} _&BnET  
wmoOp;C  
\HH|{   
public void setSFileName(String value) ]Q,RVEtKp  
{ h` n>6I  
sFileName = value; i%\nJs*  
} fWLsk  
%%-kUe  
qo}kwwWN;  
public int getNSplitter() [N$@nA-d  
{ Jg%sl& 65  
return nSplitter; t?c*(?Xa  
} r#{lpF,3Ib  
V-X n&s  
MvRuW:  
public void setNSplitter(int nCount) PUlb(3p `  
{ B,gQeW&  
nSplitter = nCount; o}Xp-P   
} 2y<d@z:K  
} bNL E=#ro  
r&TxRsg{  
!`aodz*PO  
/* VK|!aqA{b  
**Utility.java T;FzKfT|  
*/ (@&|  
package NetFox; Wx XVL"  
VD=$:F]  
*w%;$\^  
public class Utility { [KjQW/sb'  
c9ghR0WM  
xw?G?(WO  
public Utility() |E?%Cj^W  
{ neZ_TT/3K  
}  g  
#}jf TM  
} pXQ&2s$  
^Jkj/n'  
//线程睡眠 -D V;{8U4  
public static void sleep(int nSecond) 3^`bf=R  
{ w=f8UtY9@A  
try{ ^Xb!dnT.*a  
Thread.sleep(nSecond); JP@UvDE|  
} p=r{ODw#3  
catch(Exception e) 5-&P4  
{ | _S9U|  
e.printStackTrace (); b,K1EEJ  
} As>po +T*  
} -eNi;u  
-> <_J4  
//日志 T]i~GkD\  
public static void log(String sMsg) 2.:b   
{ f<zh-Gq  
System.err.println(sMsg); B! -W765Y  
} j#~4JGZt  
54 8@._-S  
dm.3.xXq  
public static void log(int sMsg) LpF6e9V\Wp  
{ =l_eliM/  
System.err.println(sMsg); 8zY)0  
} =]Ek12.  
} q$HBPR4h  
Rd#,Tl\  
i>w>UA*t  
/* +oiPj3  
**TestMethod.java X0C\87xfG  
*/ #u2PAZ@qd  
package NetFox; ?px x,o6l  
Rdv"Aj:  
c76^x   
public class TestMethod { uZ'5&k96T  
XM_S"  
wYF)G;[wM  
public TestMethod() ^.<IT"  
{ ///xx/weblogic60b2_win.exe DdFVOs|  
try{ )lW<: ?k  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8)H"w$jq  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %R_8`4IQ  
SiteFileFetch fileFetch = new SiteFileFetch(bean); =|G PSRQ  
fileFetch.start(); 5N[Y2  
} M.l;!U!}  
catch(Exception e){e.printStackTrace ();} Ao]F_hZ  
0umfC  
e~}+.B0  
} \(A>~D8Fo  
Fm2t:,=  
f.8L<<5 c  
public static void main(String[] args) Vj:PNt[  
{ =lffr?#&B  
new TestMethod(); 2s(K4~ee  
} !-7(.i-  
} [Q%3=pm_  
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:
3+5=?,请输入中文答案:八 正确答案:八