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
  • 10001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.Xn  
**SiteFileFetch.java 7<su8*?  
*/ XP)^81i|  
package NetFox; 9)wYSz'  
import java.io.*; sSU|N;"Y  
import java.net.*; wG49|!l6T  
254V)(t^QM  
\-yI dKj  
public class SiteFileFetch extends Thread { ].s;Yxz  
>B6* `3v  
vv.E6D^x(  
SiteInfoBean siteInfoBean = null; //文件信息Bean =mXC,<]  
long[] nStartPos; //开始位置 $wAR cS  
long[] nEndPos; //结束位置 Ba[,9l[  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 W yM1s+@  
long nFileLength; //文件长度 - VJx)g  
boolean bFirst = true; //是否第一次取文件 loIb}8  
boolean bStop = false; //停止标志 a <C?- g|  
File tmpFile; //文件下载的临时信息 JOuyEPy  
DataOutputStream output; //输出到文件的输出流 opH!sa@U  
Lf(( zk:pt  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 3RaW\cWzg  
public SiteFileFetch(SiteInfoBean bean) throws IOException _^W;J/He  
{ ;qaPK2 a8  
siteInfoBean = bean; :(]fC~G~  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); p q`uB  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ,NQ!d4 ~D  
if(tmpFile.exists ()) F `7 v  
{ g ` s|]VNt  
bFirst = false; 0 h A:=r  
read_nPos(); >Lo\?X~  
} >e {1e  
else bL xZ 5C7t  
{ a Vu!Qk=Z/  
nStartPos = new long[bean.getNSplitter()]; SE\?8cs]-  
nEndPos = new long[bean.getNSplitter()]; d3:GmB .  
} ,!_6X9N-h  
hdDT'+  
'4uu@?!dVk  
i2Wvu3,D3-  
} c*rH^Nz  
di/Q Jrw  
US$$ADq  
public void run() @dv8 F "v  
{ ?JZ$M  
//获得文件长度 >eA@s}_8  
//分割文件 e@vtJaSu  
//实例FileSplitterFetch ]mMJ6n  
//启动FileSplitterFetch线程 42]7N3:'  
//等待子线程返回 #_.J kY  
try{ l~"T>=jq3  
if(bFirst) SAdT#0J  
{ 2 `>a(  
nFileLength = getFileSize(); BP9#}{kE  
if(nFileLength == -1) %rb$tKk  
{ 4`i8m  
System.err.println("File Length is not known!"); )I&.6l!#  
} ~)f^y!PMQ  
else if(nFileLength == -2) ./ {79  
{ Kn:Ml4[;  
System.err.println("File is not access!"); #DgHF*GG+>  
} e%cTFwX?n  
else 3SIq od;%  
{ +4-T_m/W/  
for(int i=0;i<nStartPos.length;i++) U,P>P+\@  
{ Ms|c" ?se  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Qn8xe,  
} I]C Y>'  
for(int i=0;i<nEndPos.length-1;i++) XSC=qg$  
{ Z$/76  
nEndPos = nStartPos[i+1]; 'TS_Am?o  
} iv>MIdIm  
nEndPos[nEndPos.length-1] = nFileLength; 3A`Gx#  
} YTyrX  
} ^m%#1Zd  
Uuy$F  
0S4BV%7F  
//启动子线程 ?Ujg.xo\  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; gl+d0<R zw  
for(int i=0;i<nStartPos.length;i++) ZjmQ  
{ d 5yEgc;z  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mxqD'^n#  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {|u"I@M*O  
nStartPos,nEndPos,i); @#4-4.6I<x  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2yK">xYY@  
fileSplitterFetch.start(); ]^C 8Oh<  
} 1_TuA(  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qf(mJlU  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); cuN]}=D  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", tQ{/9bN?P  
nEndPos = " + nFileLength); ;+wB!/k,  
// fileSplitterFetch[nPos.length-1].start(); nmU1xv_  
'|4+< #  
\Sd8PGl*'  
//等待子线程结束 H<Sf0>OA  
//int count = 0; % [$HX'Y  
//是否结束while循环 7,SQz6]  
boolean breakWhile = false; Kd-1EU  
 )bF l-  
rk8pL[|  
while(!bStop) N; }$!sNIm  
{ |@AXW   
write_nPos(); Y_CVDKdcY  
Utility.sleep(500); V^,gpTyv*  
breakWhile = true; _4N.]jr5  
mU-2s%X<.^  
FPYk`D  
for(int i=0;i<nStartPos.length;i++) S-Y{Vi"2  
{ P{9:XSa%  
if(!fileSplitterFetch.bDownOver) #r9+thyC  
{ <(KCiM=E$  
breakWhile = false; -iiX!@  
break; Y$L` G  
} 1w=.vj<d8  
} 7z$Z=cs  
if(breakWhile) 2{h2]F  
break; 8b?nr;@  
D 5rH6*J  
G^Gs/- f  
//count++; U"7o;q  
//if(count>4) 4fKvB@O@.  
// siteStop(); c6[m'cy  
} >B{qPrmI  
]pvHsiI:  
iL;V5|(sb  
System.err.println("文件下载结束!"); ]W?cy  
} z}Cjk6z@  
catch(Exception e){e.printStackTrace ();} @4;'>yr(  
} lBfthLBa  
\na$Sb+  
uJ2ZHrJ  
//获得文件长度 H7'42J@  
public long getFileSize() \$_02:#  
{ "zcAYg^U  
int nFileLength = -1; $jMA(e`Ye0  
try{ U:*rlA@_.  
URL url = new URL(siteInfoBean.getSSiteURL()); <~dfp  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QG*hQh  
httpConnection.setRequestProperty("User-Agent","NetFox"); aA4RC0'  
iAH,f5T  
[k$GUU,jY  
int responseCode=httpConnection.getResponseCode(); lW c[Q1  
if(responseCode>=400) nDvfb* \  
{ sc]#T)xG  
processErrorCode(responseCode); qefp3&ls  
return -2; //-2 represent access is error QKP #wR  
} =wX;OK|U(^  
>3/ mV<g f  
'f{13-# X@  
String sHeader; q(qm3OxYo  
qR.FjQOvn  
C?|sQcCE  
for(int i=1;;i++) }p?,J8=-  
{ l?)>"^  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Wq3PN^  
//Utility.log(in.readLine()); KRxJ2  
sHeader=httpConnection.getHeaderFieldKey(i); G|jHic!  
if(sHeader!=null) >l 0aME@-0  
{ (/uN+   
if(sHeader.equals("Content-Length")) H}r]j\  
{ h> bjG  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2;sTSGDG  
break; d[?RL&hJO  
} 4vL\t uoz  
} O + aK#eF  
else qVh?%c1.Y  
break; MX]#|hEeQ  
} Lz1KDXr`)+  
} "=Z=SJ1D  
catch(IOException e){e.printStackTrace ();} h~Ir= JV  
catch(Exception e){e.printStackTrace ();} |$/#,Dv7  
g R!hN.I  
:WWHEZK  
Utility.log(nFileLength); oqvu8"  
93n%:?l"<W  
B-LV/WJ_  
return nFileLength; UhJS=YvT  
} lai@,_<GV  
eM!Oc$C8[  
e5AsX.kv B  
//保存下载信息(文件指针位置) 0dwD ?GG2  
private void write_nPos() ^JxVs 7  
{ 6/cm TT$i  
try{ w(bvs&`{uC  
output = new DataOutputStream(new FileOutputStream(tmpFile)); (tA[]ne2  
output.writeInt(nStartPos.length); jkl dr@t  
for(int i=0;i<nStartPos.length;i++) _8$xsj4_  
{ A@~9r9Uf  
// output.writeLong(nPos); pzRVX8  
output.writeLong(fileSplitterFetch.nStartPos); jy~hLEt7  
output.writeLong(fileSplitterFetch.nEndPos); NCg("n,jx  
} 2XyyU}.$  
output.close(); >0SG]er@  
} |34k;l]E  
catch(IOException e){e.printStackTrace ();} 2. nT k   
catch(Exception e){e.printStackTrace ();} |m\7/&@<  
} " :e <a?  
c*#$sZ@YA  
d0T 8Cwc b  
//读取保存的下载信息(文件指针位置) .?#Q(eLj  
private void read_nPos() \0lQ1FrY  
{ N#-%b"(  
try{ -5e8m4*  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L2Cb/!z`c  
int nCount = input.readInt(); !]R>D{""  
nStartPos = new long[nCount]; B0RVtbK  
nEndPos = new long[nCount]; v"2A?  
for(int i=0;i<nStartPos.length;i++) MX*4d{l  
{ lre(]oBXA  
nStartPos = input.readLong(); \=RV?mI3?  
nEndPos = input.readLong(); IV&5a]j  
} :{eYm|2-  
input.close(); !}|'1HIC  
} [GCaRk>b,  
catch(IOException e){e.printStackTrace ();} D+AkV|  
catch(Exception e){e.printStackTrace ();} !|9@f$Jv  
} i*l =xW;bM  
xX%{i0E  
I RLAsb3  
private void processErrorCode(int nErrorCode) "$5cKbJ  
{ QX?moW6UW  
System.err.println("Error Code : " + nErrorCode); r+Sv(KS4i^  
} ^VzhjKSu  
7lYf+&JZ  
pbh>RS=ri  
//停止文件下载 DQObHB8L  
public void siteStop() = <A0;  
{ l^tRy_T:-  
bStop = true; yEB#*}K?  
for(int i=0;i<nStartPos.length;i++) \Dr( /n  
fileSplitterFetch.splitterStop(); ,W 'P8C  
;<o?JM  
y:zNf?6&  
} B!x6N"  
} BQ,749^S  
//负责部分文件的抓取  f^}n#  
**FileSplitterFetch.java 4<<eqxI$|  
*/ Wf?[GO  
package NetFox; ?W dY{;&  
KWYjN h#*  
3it*l-i\  
import java.io.*; ,y0 &E8Z  
import java.net.*; kxrYA|x  
D @wIbU  
%Ze7d&  
public class FileSplitterFetch extends Thread { (uHyWEHt  
_^?_Vb  
nql{k/6  
String sURL; //File URL 3 %BI+1&T_  
long nStartPos; //File Snippet Start Position F1}d@^K 7d  
long nEndPos; //File Snippet End Position o]]tH  
int nThreadID; //Thread's ID Rc93Fb-Zp  
boolean bDownOver = false; //Downing is over u>] )q7s  
boolean bStop = false; //Stop identical oG hMO  
FileAccessI fileAccessI = null; //File Access interface s,mt%^x[  
/ZL6gRRA|  
non5e)w3@  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3:w_49~: ~  
{ |A|K);  
this.sURL = sURL; )yz)Fw|&  
this.nStartPos = nStart; Bs '=YK$  
this.nEndPos = nEnd; kTzO4s?  
nThreadID = id; [@pumH>  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Z"l].\= F  
} 0}` -<(  
`Y!8,( 5#  
=(R3-['QIb  
public void run() i$.!8AV6  
{ ]l=CiG4!M  
while(nStartPos < nEndPos && !bStop) r0OP !u  
{ D\-DsT.H  
.f[z_% ar  
Gf!c  
try{ I~HA ad,k  
URL url = new URL(sURL); Yp3y%n  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Te3 ?z  
httpConnection.setRequestProperty("User-Agent","NetFox"); y(a>Y! dgU  
String sProperty = "bytes="+nStartPos+"-"; all2?neK  
httpConnection.setRequestProperty("RANGE",sProperty); ([SJ6ff]&  
Utility.log(sProperty); ,1t|QvO  
2/F8kVx{  
 '"hSX=  
InputStream input = httpConnection.getInputStream(); ;i [;%  
//logResponseHead(httpConnection); oFzmH!&ED  
@eESKg(,  
jW^]N$>  
byte[] b = new byte[1024]; . Y!dO@$:  
int nRead; ]R^xO;g'  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1;,<UHF8N  
{ N3)n**  
nStartPos += fileAccessI.write(b,0,nRead); d|gfp:Z`a  
//if(nThreadID == 1) H4wDF:n0H  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~XXNzz ]?  
} JCB3 BZg7&  
_$vbb#QXZG  
T' Jl,)"  
Utility.log("Thread " + nThreadID + " is over!"); =RM]/O9  
bDownOver = true; IQ$6}.  
//nPos = fileAccessI.write (b,0,nRead); |~v2~   
} ]X X>h~0  
catch(Exception e){e.printStackTrace ();} {EVy.F  
} ^mut-@ N9  
} !F Zg' 9  
C0^r]^$Z  
$EdL^Q2KAy  
//打印回应的头信息 fU.z_ T[@  
public void logResponseHead(HttpURLConnection con) (_N(K`4#W  
{ U9\w)D|+eE  
for(int i=1;;i++) D deKZ)8  
{ ]Ee$ulJ02  
String header=con.getHeaderFieldKey(i); eT2Tg5Etc  
if(header!=null) #op0|:/N  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .WBp!*4  
Utility.log(header+" : "+con.getHeaderField(header)); v@fy*T\3  
else cQ`0d3  
break; s? Gv/&  
} s=K?-O  
} CLuQ=-[|  
:S-{a  
wq8&2(|Fc  
public void splitterStop() h >Z`&  
{ _0ZBG(  
bStop = true; (7$BF~s:,  
} Nn?$}g  
xbCQ^W2YU|  
^8dCFw.rU  
} ]1[:fQF7/L  
.E7"Lfs-  
alsD TQ'  
/* \IqCC h  
**FileAccess.java n7/&NiHxv/  
*//文件访问(定位,写) nYBa+>3BDf  
package NetFox; ^nFP#J)_5  
import java.io.*; ?1LRR ;-x  
^q|W@uG-(  
?jvuTS2  
public class FileAccessI implements Serializable{ 4#t-?5"  
ttBqp|.?S  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U?5G%o(q  
RandomAccessFile oSavedFile; :FmH=pI!=  
long nPos; m|OB_[9  
lO0}  
Jy('tfAHp  
public FileAccessI() throws IOException e:rbyzf#  
{ ]8'PLsS9<w  
this("",0); t4hc X[  
} $e  uI  
PY+4OZ$  
Qf'g2 \  
public FileAccessI(String sName,long nPos) throws IOException )NqRu+j  
{ z"Cyjmg"  
oSavedFile = new RandomAccessFile(sName,"rw"); O{U j  
this.nPos = nPos; `'pAiu  
oSavedFile.seek(nPos); a#9pN?~  
} y(^\]-fE  
.t&G^i'n  
Zzb?Nbf  
public synchronized int write(byte[] b,int nStart,int nLen) G9GLRdP  
{ ekmWYQ ~  
int n = -1; uK ,W  
try{ :V_UJ3xf  
oSavedFile.write(b,nStart,nLen); F'B0\v =  
n = nLen; J`{  o`>  
} n@q- f-2  
catch(IOException e) N8J(RR9O  
{ S a}P |qI  
e.printStackTrace (); cz|?j  
} @*|T(068&  
UG}2q:ST  
P^ <to(|  
return n; 3Y&4yIx  
} =([4pG  
dt"&  
_8\B~;0  
} +!$`0v   
}WBHuVcZG  
Tb8r+~HK  
/* de TD|R  
**SiteInfoBean.java dT (i*E\j  
*/ ^r mQMjF  
package NetFox; <~:2~r  
T4[/_;1g  
pmO0/ty  
public class SiteInfoBean { i` ay9J8N  
,@Kn@%?$  
Hk(=_[S  
private String sSiteURL; //Site's URL kJNwA8 7  
private String sFilePath; //Saved File's Path h@y>QhYU0  
private String sFileName; //Saved File's Name (Fq:G) $  
private int nSplitter; //Count of Splited Downloading File 9b@yDq3hQ  
tE-g]y3  
1xh7KBr,  
public SiteInfoBean() t% <y^Wa=  
{//nSplitter的缺省值为5 >[~7fxjK-  
//default value of nSplitter is 5 dep"$pys>  
this("","","",5); j0(jXAc;UB  
} J(w FJg\/  
m - hZ5 i  
8%xBSob{j  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1-&L-c.  
{ fc[_~I'  
sSiteURL= sURL; }6=)w@v  
sFilePath = sPath; A5%$<  
sFileName = sName; gFT lP  
this.nSplitter = nSpiltter; }d;6.~Gw  
<iGW~COd  
5}Xi`'g,  
} NSH4 @x  
/H3w7QU  
P|]r*1^5  
public String getSSiteURL() U4yl{?  
{ =)gdxywoC  
return sSiteURL; KC9e{  
} ?)(-_N&T  
#N'9 w .  
DH.UJ +  
public void setSSiteURL(String value)  p(8@  
{ *c&|2EsZ  
sSiteURL = value; x}V&v?1{5  
} ^H{YLO  
=Vazxt@[  
' 2O @  
public String getSFilePath() nAAv42j[  
{ fFWi 3.  
return sFilePath; Hrph>v  
} 6 .)Xeb"  
3eXIo=  
vLyazVj..  
public void setSFilePath(String value) B&0 W P5OF  
{ %~gI+0HK  
sFilePath = value; 7mMMVz2  
} cO 5zg<wF  
+mzLOJed  
$bFK2yx?=  
public String getSFileName() 22U`1AD3U  
{ S6 a\KtVa  
return sFileName; (Cfb8\~  
} QCE7VV1Rw  
0Oc?:R'$  
$(]nl%<Q  
public void setSFileName(String value) X{OWDy  
{ !2Z"Lm  
sFileName = value; i1-%#YYF(  
} /]MelW  
%Ta"H3ZW  
x\f~Gtt7Y  
public int getNSplitter() Gn_DIFa  
{ (V]3w  
return nSplitter; P)J-'2{  
} w^$C\bCbh  
j%^4 1y  
Y?3tf0t/  
public void setNSplitter(int nCount) hpPacN  
{ y$SUYG'v  
nSplitter = nCount; |5O>7~Tp  
} $~W5! m  
} &} `a"tYr  
=!xX{o?64  
q CYu@Ho  
/* wWiYxBeN  
**Utility.java El;"7Qn  
*/ <r$h =hM  
package NetFox; g=Vu'p 3u  
$Th)z}A}EA  
$T^q>v2u  
public class Utility { &ah%^Z4um  
oW 6Hufu+o  
t"q'"FX  
public Utility() nReld :#T  
{ vZ"gCf3#?3  
m m`#v g,  
"QxULiw  
} \y]K]iv  
dnU-v7k,{  
//线程睡眠 .hR <{P  
public static void sleep(int nSecond) 4n7Kz_!SVf  
{ ._^ne=Lx  
try{ L-C^7[48=  
Thread.sleep(nSecond); 9Ffam#  
} zIjfx K  
catch(Exception e) tm^joK[{|J  
{ ZL\^J8PRK  
e.printStackTrace (); Q47R`"  
} J 3C^tV  
} RO,TNS~  
7Y(Dg`8G  
//日志 \&;y:4&l8  
public static void log(String sMsg) $5)#L$!,]  
{ UGy3 B)  
System.err.println(sMsg); to</  
} ,.>9$(s  
i#t-p\Tcz  
-ZZJk-::  
public static void log(int sMsg) 4^l9d  
{ 4oiE@y&{4  
System.err.println(sMsg); L%is"NZh  
} d$3md<lIB  
} >{tn2Fkg>  
6{=U= *  
AG=PbY9  
/* 0P9\;!Y  
**TestMethod.java dR1IndZl  
*/ *YvtT (Gt  
package NetFox; ;'8P/a$  
&zX  W  
H/x0'  
public class TestMethod { x"e;T,c  
ION o&~-l  
vjx'yh|  
public TestMethod() * $fM}6}  
{ ///xx/weblogic60b2_win.exe xsj ,l@Ey  
try{ K6p\ >J  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); nsU7cLf"^V  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N'WTIM3W  
SiteFileFetch fileFetch = new SiteFileFetch(bean); vHcl7=)Q  
fileFetch.start(); RdWn =;  
} KYm8|]'g  
catch(Exception e){e.printStackTrace ();} s0f+AS|}  
)__sw  
l! 88|~  
} u0&R*YV  
>B**fZ~L  
ZY`9  
public static void main(String[] args) Uq#2~0n>  
{ ~&D =;M/  
new TestMethod(); v.Bwg 7R3  
} A&t8C8,  
} `+n#CWZ"Y  
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