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
  • 10211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
/* ukY"+&  
**SiteFileFetch.java ,1##p77.  
*/ uH-)y,2&  
package NetFox; hG:|9Sol,  
import java.io.*; O#u=c1 ?:  
import java.net.*; (b6NX~G-:  
5BJmA2L  
A={UL  
public class SiteFileFetch extends Thread { nQ L@hc  
'Qo*y%{@5  
*|E[L^  
SiteInfoBean siteInfoBean = null; //文件信息Bean M:6"H%h,W  
long[] nStartPos; //开始位置 EU/8=JA1  
long[] nEndPos; //结束位置  JSg$wi8  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 jZ3fKyp#   
long nFileLength; //文件长度 Zr,VR-kW+  
boolean bFirst = true; //是否第一次取文件 TNr :pE<  
boolean bStop = false; //停止标志 i@R 1/M  
File tmpFile; //文件下载的临时信息 LYg- .~<I  
DataOutputStream output; //输出到文件的输出流 Cs ifKHI  
d5z`BH.  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) *r% c  
public SiteFileFetch(SiteInfoBean bean) throws IOException 9RI-Lq`  
{ j9OG\m  
siteInfoBean = bean; u=_mvN  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); -\n@%$M]G  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); E\2%E@0#  
if(tmpFile.exists ()) 8Dm%@*B^b  
{ AZ}Xj>=  
bFirst = false; SN!?}<|U  
read_nPos(); ?8Cq{  
} #`X?=/q  
else }I6vqG  
{ fe#\TNeQJ[  
nStartPos = new long[bean.getNSplitter()]; NS6:yX,/  
nEndPos = new long[bean.getNSplitter()]; Q'mM3pq4r  
} !o[7wKrXb  
Oh\<VvZuN  
=k:,qft2  
xLZG:^(I  
} S +^E.  
_aMPa+D=P  
yD6[\'%  
public void run() {LQ#y/H?  
{ 0|\$Vp  
//获得文件长度 }t1a* z  
//分割文件 yw3$2EW  
//实例FileSplitterFetch )sp4Ie  
//启动FileSplitterFetch线程 f_Av3  
//等待子线程返回 %lGfAYEM=  
try{ 2q4<t:!  
if(bFirst) xZF}D/S?Ov  
{ 6ez<g Uf  
nFileLength = getFileSize(); 0aa&m[Mk  
if(nFileLength == -1) PJrtM AcKq  
{ X~,aNRy  
System.err.println("File Length is not known!"); WoRZW%  
} Eq\M;aDq  
else if(nFileLength == -2) `&sH-d4v  
{ zXxT%ZcCj  
System.err.println("File is not access!"); O ,h;hQZ  
} oVe|M ss6  
else 8j % Tf;  
{ vV e';|8v  
for(int i=0;i<nStartPos.length;i++) Jrpx}2'9:a  
{ &,CiM0  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); b4ONh%  
} iBgx  
for(int i=0;i<nEndPos.length-1;i++) YCM]VDx4u1  
{ :'l^kSP_*C  
nEndPos = nStartPos[i+1]; !~D}/Q;#}\  
} \\dM y9M-  
nEndPos[nEndPos.length-1] = nFileLength; i||]V*5n  
} M`i\VG  
} {|:;]T"y  
c%G{#}^2  
@A89eZbW  
//启动子线程 LS*y  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &wCg\j_c  
for(int i=0;i<nStartPos.length;i++) ;J2zp*|  
{ ZR?yDgL  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), EYEnN  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /qGf 1MHD  
nStartPos,nEndPos,i); &*G #H~\  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9:1Q1,-i!-  
fileSplitterFetch.start(); QpA/SmJ  
} ( _)jkI \  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), giIWGa.a+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,TN 2  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,>-< (Qi  
nEndPos = " + nFileLength); 1Z~)RJ<D  
// fileSplitterFetch[nPos.length-1].start(); p@5`& Em,  
tlqiXh<  
e`TH91@  
//等待子线程结束 C:C}5<fk x  
//int count = 0; )V6Hl@v  
//是否结束while循环 X/2&!O  
boolean breakWhile = false; Z9 9>5\k  
Q[pV!CH  
vUU9$x  
while(!bStop) L=8<B=QT$  
{ 6%Pdy$ P  
write_nPos(); 0#&5.Gr)  
Utility.sleep(500); J/GSceHF  
breakWhile = true; xScLVt<\e  
af+IP_6 .  
7Ka l"Ew  
for(int i=0;i<nStartPos.length;i++) #9xd[A : N  
{ hKjt'N:~ZY  
if(!fileSplitterFetch.bDownOver) g,95T Bc  
{ h`k"A7M  
breakWhile = false; T}P".kpbS  
break; H_ox_ u}  
} xp72>*_9&  
} k |%B?\m  
if(breakWhile) be-~\@  
break; mkF"   
?zVL;gVWA  
wl$h4 {L7  
//count++; D-(w_$#  
//if(count>4) q+]h=:5=I  
// siteStop(); ( %xwl  
} &c%g  
okv1K  
BT"42#7_  
System.err.println("文件下载结束!"); rT5Ycm@  
} +0q>fp_K(+  
catch(Exception e){e.printStackTrace ();} 2e9es  
} }S$@ Ez6  
_DNHc*  
ugx%_x6  
//获得文件长度 LLXVNO@e+  
public long getFileSize() .j>hI="b  
{ Ej>g.vp8I  
int nFileLength = -1; I=9!Rs(QF  
try{ p4i]7o@  
URL url = new URL(siteInfoBean.getSSiteURL()); -3lb@ 6I6  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 09kt[  
httpConnection.setRequestProperty("User-Agent","NetFox"); S'B|>!z@  
/3:q#2'v  
OP|8Sk6 r  
int responseCode=httpConnection.getResponseCode(); )V:]g\t  
if(responseCode>=400) deixy. |  
{ -!L"')  
processErrorCode(responseCode); `zt_7MD  
return -2; //-2 represent access is error jDN ]3Y`  
} -7&Gi +]  
0`A~HH}  
!i%"7tQ3$  
String sHeader; BC;:  
]&{ci  
,qrQ"r9  
for(int i=1;;i++) g{9+O7q  
{ ^e>Wo7r  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); lmSo8/%T  
//Utility.log(in.readLine()); 4[-*~C|W5  
sHeader=httpConnection.getHeaderFieldKey(i); >ap1"n9k  
if(sHeader!=null) dG71*)<)t  
{ ^~HQC*  
if(sHeader.equals("Content-Length")) {; >Q.OX@  
{ ^F"iP7   
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); e=QK}gzX  
break; ~E^,=4  
} rzI|?QaPi  
} vuFBET,  
else UD y(v]  
break; R?EASc!b  
} $VQtwuYt  
} ) (Tom9 ^  
catch(IOException e){e.printStackTrace ();} `H3.,]  
catch(Exception e){e.printStackTrace ();} X*7\lf2  
$CE[MZ&S  
eV cANP  
Utility.log(nFileLength); J!*/a'Cv  
LR,7,DH$9'  
|J~eLh[d  
return nFileLength; #s%-INcR  
} O!Z|r ?  
nD2, !71  
5]1h8PW!Y  
//保存下载信息(文件指针位置) R, 8s_jN  
private void write_nPos() 1lnU77;  
{ 8g >b  
try{ .~gl19#:T  
output = new DataOutputStream(new FileOutputStream(tmpFile)); *X38{r j  
output.writeInt(nStartPos.length); j` /&r*zNq  
for(int i=0;i<nStartPos.length;i++) 8Z2.`(3c[  
{ do ^RF<G  
// output.writeLong(nPos); OW(&s,|6x  
output.writeLong(fileSplitterFetch.nStartPos); N|2y"5  
output.writeLong(fileSplitterFetch.nEndPos); +/+P\O  
} #DkD!dW(l  
output.close(); &wetzC )  
} t%r :4,  
catch(IOException e){e.printStackTrace ();} O8N[Jl  
catch(Exception e){e.printStackTrace ();} v}v 5  
} 0X(]7b&~R  
L{ymI) Y^  
vY*\R0/a  
//读取保存的下载信息(文件指针位置) wn11\j&  
private void read_nPos() W:QwHZ2O  
{ sxED7,A  
try{ $YG1z  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [[)_BmS5r  
int nCount = input.readInt(); ~L+]n0*  
nStartPos = new long[nCount]; NgB 7?]vu  
nEndPos = new long[nCount]; +TRy:e  
for(int i=0;i<nStartPos.length;i++) I 2HT2c$  
{  \`xkp[C  
nStartPos = input.readLong(); u>Ki$xP1  
nEndPos = input.readLong(); S C_|A9  
} >AI<60/<  
input.close(); } IlP:  
} YbMssd2Yg  
catch(IOException e){e.printStackTrace ();} 1ZKzumF  
catch(Exception e){e.printStackTrace ();} C/v}^#cLD  
} j:1uP^.  
O(OmGu4%  
i.rU&yT%  
private void processErrorCode(int nErrorCode) V_L[P9  
{ CM~MoV[k7e  
System.err.println("Error Code : " + nErrorCode); -'C!"\%  
} amB@N6*  
G+Dpma ]  
*PM}"s  
//停止文件下载 Gz dgL"M[  
public void siteStop() &P n]  
{ ,sb1"^Wc  
bStop = true; Rk<%r k  
for(int i=0;i<nStartPos.length;i++) {~GR8 U  
fileSplitterFetch.splitterStop(); MtG_9-  
K ~>jApZ%  
_9h.Gt  
} $au2%NL  
} @ u1Q-:  
//负责部分文件的抓取 ?*K<*wBw#  
**FileSplitterFetch.java .k]#XoE  
*/ 4 10:%WGc  
package NetFox; OKQLv+q5K)  
<-|SIF  
Y(GW0\<  
import java.io.*; glor+  
import java.net.*; 31 ] 7z  
M1uP\Sa  
Jn,w)Els  
public class FileSplitterFetch extends Thread { Ve14rn  
j<$R4A 1  
A[ 1)!e  
String sURL; //File URL d[U1.SNL  
long nStartPos; //File Snippet Start Position FR'b`Xv:  
long nEndPos; //File Snippet End Position ^I./L)0= }  
int nThreadID; //Thread's ID -y8?"WB(b  
boolean bDownOver = false; //Downing is over 6cCC+*V{  
boolean bStop = false; //Stop identical ^Vl{IsY  
FileAccessI fileAccessI = null; //File Access interface aY^_+&&G  
67Z.aaXD1  
] ~;x$Z)  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException __}j {Buk  
{ v&[Ff|>  
this.sURL = sURL; 93z oJiLRf  
this.nStartPos = nStart; JEF2fro:Z  
this.nEndPos = nEnd; N# Ru `;  
nThreadID = id; ,W"[q~  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vT*z3  
} Vb0((c%&  
_Y7uM6HL\  
`"N56  
public void run() "3kIQsD|j  
{ ?v]EXV3  
while(nStartPos < nEndPos && !bStop) ] m$;ra]  
{ NaeG2>1  
kaSy 9Y{  
nLn3kMl4  
try{ 58x=CN\QU  
URL url = new URL(sURL); y.$/niQ%  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VdrqbZ   
httpConnection.setRequestProperty("User-Agent","NetFox"); LKCj@NdV  
String sProperty = "bytes="+nStartPos+"-"; o6JCy\Bx  
httpConnection.setRequestProperty("RANGE",sProperty); MfJ;":]O!  
Utility.log(sProperty); L&[uE;ro  
3P{ d~2  
Pr |u_^  
InputStream input = httpConnection.getInputStream(); 9M3XHj  
//logResponseHead(httpConnection); |@{4zoP_N  
~x:\xQti  
sEpY&6*  
byte[] b = new byte[1024]; FerQA9K)x  
int nRead; RR,gC"cTi  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ao2NwH##  
{ T%{qwZc+mJ  
nStartPos += fileAccessI.write(b,0,nRead); 1P (5+9"s  
//if(nThreadID == 1) MeD}S@H  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vM_UF{a$=  
} :#CQQ*@  
c&!EsMsU  
)f#raXa5+  
Utility.log("Thread " + nThreadID + " is over!"); +n]z'pijb  
bDownOver = true; [1 pWg^  
//nPos = fileAccessI.write (b,0,nRead); 13+f ^  
} JQ-O=8]  
catch(Exception e){e.printStackTrace ();} L9,;zkgo  
} 60 D0z  
} *G'R+_tdE  
N3J T[7  
iUNlNl ?  
//打印回应的头信息 3em&7QM  
public void logResponseHead(HttpURLConnection con) " 3ryp A  
{ r]GG9si  
for(int i=1;;i++) M1{ru~Z9  
{ ,ALEfepo  
String header=con.getHeaderFieldKey(i); F+%6?2 J  
if(header!=null) Ie12d@  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PVK. %y9  
Utility.log(header+" : "+con.getHeaderField(header)); Y9YE:s  
else ^0 zWiX  
break; _J|cJ %F>%  
} 0rnne L  
} lCyBdY9n  
oP[R?zN  
$2tPqZ>  
public void splitterStop() B,2oA]W"S  
{ y(^hlX6gQ  
bStop = true; /' +GYS  
} UEm~5,>$0  
S,Y\ox-  
x{GKz#  
} Z@Tb3N/[  
{x&"b-  
@;^7kt  
/* #YABb wH  
**FileAccess.java WUEjWJA-MB  
*//文件访问(定位,写) 1[? xU:;9  
package NetFox; pwu8LQ3b{O  
import java.io.*; ]]R!MnU:$  
Iu3*`H  
h'QEwW  
public class FileAccessI implements Serializable{ N:4oVi@Je  
\A~r~  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 E%+aqA)f  
RandomAccessFile oSavedFile; e*nT+Rp  
long nPos; <@+>A$~0  
@bkZ< Gq  
{c#{dT  
public FileAccessI() throws IOException Y6&B%t<bo  
{  !623;   
this("",0); CrTGC%w{=  
} E0SP  
yf lt2 R  
dg(fD>+  
public FileAccessI(String sName,long nPos) throws IOException 7KB:wsz^  
{ |=\w b^l+  
oSavedFile = new RandomAccessFile(sName,"rw"); Z'u:Em  
this.nPos = nPos; W7sx/O9  
oSavedFile.seek(nPos); BAJEn6f?  
} #iZ%CY\  
A_:YpQ07@  
8J5{}4s\f  
public synchronized int write(byte[] b,int nStart,int nLen) @P$_2IU"  
{ =7*k>]o  
int n = -1; {H\(H _X  
try{ >$%rsc}^  
oSavedFile.write(b,nStart,nLen); + A=*C  
n = nLen; NHL -ll-R  
} _&]B  
catch(IOException e) 9=-d/y?  
{ O<:"Irq\qr  
e.printStackTrace (); -0tHc=\u(  
} P ~sX S  
V~9s+>  
DGQGV[9%4C  
return n; YNRorE   
} nw)yK%`;M  
"1#piJ  
9q4%s?)j  
} pyf/%9R:d  
4ox[,  
;I#f:UQ  
/* M?3N h;  
**SiteInfoBean.java 'f?=ks<  
*/ 7Zf * T  
package NetFox; AJ:(NV1=  
Q&X#( 3&'  
G<8d=}  
public class SiteInfoBean { Q;'{~!=  
o-m9}pV  
I 'qIc ?  
private String sSiteURL; //Site's URL 2,3pmb  
private String sFilePath; //Saved File's Path %]iDhXLr  
private String sFileName; //Saved File's Name +im>|  
private int nSplitter; //Count of Splited Downloading File !n?8'eqWru  
^e 1Ux  
`E4+#_ v  
public SiteInfoBean() q>E[)\+y  
{//nSplitter的缺省值为5 Hl3%+f  
//default value of nSplitter is 5 : }q~<  
this("","","",5); v'vYN h  
} 6^'BhHP  
{tN?)~ZQ  
S%sD#0l  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L2L=~/LG  
{ 8}^R jMgI  
sSiteURL= sURL; k'(eQ5R3L  
sFilePath = sPath; t@Bl3Nt{  
sFileName = sName; 4fq:W`9sN  
this.nSplitter = nSpiltter; k|Syw ATr  
mbS`+)1=l  
CHojF+e  
} !UV1OU  
wt(Hk6/B  
)v+R+3<  
public String getSSiteURL() ?c;T4@mB  
{ ?C6DK{S(  
return sSiteURL; z^etH/]Sy  
} icw (y(W  
*2(W`m  
43HZ)3!me  
public void setSSiteURL(String value) 'WC> _ L  
{ us0{y7(p  
sSiteURL = value; %^?yI  
} A@o:mZ+XN(  
4L`<xX;:{  
M#?^uu'  
public String getSFilePath() ydx-` yg#  
{ jO9w7u6  
return sFilePath; c'XvZNf .C  
} qVidubsW  
-UMPt"o  
?L'4*S]  
public void setSFilePath(String value) pT ;{05  
{ s&gzv=v  
sFilePath = value; dPtQ Sa  
} +,H6)'#Z  
B4>kx#LR  
CB1AL]|3  
public String getSFileName() wRATe 0'  
{ @ a$HJ:  
return sFileName; K5ywO8_6`  
} IdzrQP  
M.loG4r!  
*@C]\)  
public void setSFileName(String value) +I9+L6>UR  
{ 2o\GU  
sFileName = value; Z ^w5x:  
} JBCJVWUt  
;Bs^+R7  
eT4+O5t  
public int getNSplitter() #SR"Q`P  
{ F[65)"^  
return nSplitter; DKzP)!B "  
} :q+D`s  
jxt^d  
2Q/#.lNL  
public void setNSplitter(int nCount) GkutS.2G#  
{ vcsMU|GGh  
nSplitter = nCount; rf%NfU  
} T&5dF9a  
} <> &!+|#  
fV` R7m.  
 B3Yj  
/* t\p_QWnF  
**Utility.java v8< MAq  
*/ dF- d  
package NetFox; `T;M=S^y*E  
?b&~(,A{  
-i}@o1o\  
public class Utility { &;)6G1X1  
/wj L<  
>H ,t^i}@  
public Utility() D-zqu~f`  
{ @Lj28&4:<  
$jDp ^ -  
<( 0TK5  
} aXSTA ,%  
.-:R mYGR  
//线程睡眠 <.d0GD`^  
public static void sleep(int nSecond) {FavF 9O  
{ ^c9~~m16+  
try{ fRTQ5V  
Thread.sleep(nSecond); xY/ S;dE  
} w:}RS.AK  
catch(Exception e) uQ;b'6Jcp  
{ XG5mfKMt+  
e.printStackTrace (); e/?>6'6 5  
} y`~[R7E  
} =9oN#4mWK  
C#5z!z/:%  
//日志 Hm?zMyO.k  
public static void log(String sMsg) kpkN GQ2  
{ Ou _bM n  
System.err.println(sMsg); ]hBp elKJ  
} Um k9  
@x>J-Owd]J  
c%uX+\-$  
public static void log(int sMsg) %} _{_Z  
{ -P09u82  
System.err.println(sMsg); 1RtbQ{2F;  
} [Hn4&PET  
} gE/O29Y  
 /{ .  
#:v e3gWl  
/* 7W[}7Y   
**TestMethod.java "28b&pm  
*/ ,y[wS5li  
package NetFox; 9L}=xX`>?  
h Znq\p~  
d/8I&{.  
public class TestMethod { ?hh 4M  
2 $^n@<uZ@  
R=IZFwr  
public TestMethod() C?e1 a9r  
{ ///xx/weblogic60b2_win.exe DiyviH  
try{ n>tYeN)F<  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *5k" v"NM(  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); M`$s dZ"  
SiteFileFetch fileFetch = new SiteFileFetch(bean); QvK-3w;=  
fileFetch.start(); e9;<9uX  
} O_#Ag K<A  
catch(Exception e){e.printStackTrace ();} <wge_3W#  
sO~:e?F  
oagxTFh8~  
} K.?~@5%  
'dYjbQ}~;  
TY[1jW~{r  
public static void main(String[] args) Kd8V,teH  
{ j?ihUNY!+  
new TestMethod(); D!kv+<+  
} JPQ[JD^]  
} q1sK:)Hu+  
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
如果您提交过一次失败了,可以用”恢复数据”来恢复帖子内容
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八