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
  • 8507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
/* QymD-A"P  
**SiteFileFetch.java 3;y_mg  
*/ E@pFTvo  
package NetFox; F= i!d,S  
import java.io.*; sqG`"O4W  
import java.net.*; xF8 :^'  
/=ylQn3 *  
7;xKy'B\  
public class SiteFileFetch extends Thread { q\H7& w  
1+^n!$  
xG%*PNM0q  
SiteInfoBean siteInfoBean = null; //文件信息Bean F+*Q <a4  
long[] nStartPos; //开始位置 %6]\^  
long[] nEndPos; //结束位置 4oJ$dN  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 +/q0Y`v  
long nFileLength; //文件长度 yW> RRE;  
boolean bFirst = true; //是否第一次取文件 -+P7:4/  
boolean bStop = false; //停止标志 .)`-Hkxa  
File tmpFile; //文件下载的临时信息 F< |c4  
DataOutputStream output; //输出到文件的输出流 `a'` $'j  
a#QBy P  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ('d{t:TsY  
public SiteFileFetch(SiteInfoBean bean) throws IOException b42QBTeg  
{ XRa#2 1pQ  
siteInfoBean = bean; @1.9PR$x  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ]fC7%"nB  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); IMaYEO[  
if(tmpFile.exists ()) $8@+j[>  
{ [ &daG:  
bFirst = false; STB-guia5  
read_nPos(); mJ$Htyr  
} Tc_do"uU  
else 6ZksqdP8  
{ pqq?*\W&[v  
nStartPos = new long[bean.getNSplitter()]; \HG$V>2  
nEndPos = new long[bean.getNSplitter()]; } J(1V!EA  
} ]ymC3LV]  
(UcFNeo  
 tgW kX  
8uA<G/Q;  
} 4NUN Ov`[{  
4:3_ER]J  
dXO=ZU/N  
public void run() {F!v+W>  
{ u _X} -U  
//获得文件长度 v= 8VvT 8  
//分割文件 I>Y{>S  
//实例FileSplitterFetch I61%H9 ;  
//启动FileSplitterFetch线程 ;^ov~PPl  
//等待子线程返回 >13/h]3  
try{ fz8h]PZ  
if(bFirst) Hf_'32e3<  
{ 0etwz3NuW  
nFileLength = getFileSize(); -t>Z 9  
if(nFileLength == -1) M8_R  
{ hr1$1&p  
System.err.println("File Length is not known!"); .qinR 6=  
} 9A<0zt  
else if(nFileLength == -2) *|poxT G  
{ InN{^uN  
System.err.println("File is not access!"); cD8Ea(  
} ,-:a?#f>  
else P57GqT  
{ EW9b*r7./  
for(int i=0;i<nStartPos.length;i++) g? I!OG  
{ ifHU|0_=  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); sW'6} ^Q  
} -%=RFgU4  
for(int i=0;i<nEndPos.length-1;i++) f?5A"-NS  
{ Ge1duRGa  
nEndPos = nStartPos[i+1]; GoL|iNW`  
} req-Q |  
nEndPos[nEndPos.length-1] = nFileLength; (GNEYf|  
} L ]*`4 L  
} 7@@<5&mN  
LU G9 #.  
p2^)2v  
//启动子线程 j%u8=  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E@mkm  
for(int i=0;i<nStartPos.length;i++) ,P~QS  
{ !U[:5@s06  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 369Zu4|u  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), FH[#yq.Pr  
nStartPos,nEndPos,i); + "zYn!0  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )r pD2H  
fileSplitterFetch.start(); {s9<ej~<R  
} \H[Yyp4  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d QDLI  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); qzHU)Ns(_  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", FSe5k5  
nEndPos = " + nFileLength); L,W:,i/C  
// fileSplitterFetch[nPos.length-1].start(); 7P c(<Ui+  
{yU0D*#6  
cTy'JT7  
//等待子线程结束 J7Sx!PQ  
//int count = 0; u9,=po=+7f  
//是否结束while循环 JeL~]F  
boolean breakWhile = false; 18rp; l{  
-`g J  
LGXZx}4@;  
while(!bStop) 1Df, a#,y"  
{ %2,/jhHL  
write_nPos(); X]MTaD.t  
Utility.sleep(500); FF jRf  
breakWhile = true; s_S$7N`ocS  
G4O3h Y.`  
lm!F M`m  
for(int i=0;i<nStartPos.length;i++) CMFC"eS e  
{ <irpmRQr  
if(!fileSplitterFetch.bDownOver) xlk5Gob*  
{ ;8uHRcdQ  
breakWhile = false; E;$$+rA  
break; ]y}Zi/zh  
} d&?F#$>7|  
} L@+Z)# V  
if(breakWhile) h*l cEzG?A  
break; sX Z4U0 #  
zNwc((  
,k\/]9  
//count++; *iYMX[$  
//if(count>4) vU7&'ca  
// siteStop(); EFeAr@nj  
} T"IW Jpc  
1B(G]o_>!  
PH[4y:^DN  
System.err.println("文件下载结束!"); i:{:xKiCa  
} IE|, ~M2  
catch(Exception e){e.printStackTrace ();} Pm~,Ky&Hl  
} 9V.+U7\w  
C!hXEtK  
g(1"GKg3K  
//获得文件长度 Y1|^>C#a  
public long getFileSize() |MVV +.X  
{ VYHOk3  
int nFileLength = -1; Ls(&HOK[p  
try{ KjC[q  
URL url = new URL(siteInfoBean.getSSiteURL()); 8cB=}XgYS  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @::lJDGVv  
httpConnection.setRequestProperty("User-Agent","NetFox"); 50COL66:7  
G%Y*q(VrEu  
\_?yzgf  
int responseCode=httpConnection.getResponseCode(); (&k') ff9K  
if(responseCode>=400) .a5X*M]  
{ s* @QT8%  
processErrorCode(responseCode); 3mybG%39  
return -2; //-2 represent access is error am3V9 "\  
} @kS|Jz$iY  
w~ijD ^ g  
2UQN*_  
String sHeader; FX cc1X/  
ta@ ISRK  
wQ@Zw bx  
for(int i=1;;i++) f]hBPkZ6  
{ haN"/C^  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2lF WW(  
//Utility.log(in.readLine()); A(PE  
sHeader=httpConnection.getHeaderFieldKey(i); n&(3o6i'  
if(sHeader!=null) ,#=eu85 '  
{ ixg\[5.Q+  
if(sHeader.equals("Content-Length")) vs* >onCf  
{ *13g <#$  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Xad G\_?t`  
break; L(W%~UGN V  
} LE<:.?<Z-  
} PKl]Geg P  
else i[mC3ghM6,  
break; !'+\]eA  
} :{x!g6bK@  
} t$tsWAmiA[  
catch(IOException e){e.printStackTrace ();} ' l|41wxk  
catch(Exception e){e.printStackTrace ();} u<x[5xH+  
LAj}kW~  
Oib[\O7[z  
Utility.log(nFileLength); bN]\K/  
tWcizj;?wK  
cPV5^9\T  
return nFileLength; N|bPhssFw  
} 7sCR!0  
E*Pz <  
| pF5`dX  
//保存下载信息(文件指针位置) F@B  
private void write_nPos() 4 `j,&=  
{ ys:1Z\$P  
try{ 4F}g(  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?a*fy}A|  
output.writeInt(nStartPos.length); D1oaG0  
for(int i=0;i<nStartPos.length;i++) od;Bb  
{ h<+PP]l=  
// output.writeLong(nPos); -7&^jP\,  
output.writeLong(fileSplitterFetch.nStartPos); lO%MyP  
output.writeLong(fileSplitterFetch.nEndPos); s@/B*r9  
} vd2uD2%con  
output.close(); b5lk0jA  
} :y4)qF  
catch(IOException e){e.printStackTrace ();} <)r,CiS  
catch(Exception e){e.printStackTrace ();} ' m  
} ZD$-V 3e`  
j0ci~6&b3_  
3WQRN_  
//读取保存的下载信息(文件指针位置) v(i1Z}*b  
private void read_nPos() MtMvpHk  
{ .CIbpV?T  
try{ ORUWsl Mt  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); F<6KaZ|  
int nCount = input.readInt(); a7ub.9>  
nStartPos = new long[nCount];  EGp~Vo-  
nEndPos = new long[nCount]; )6O\WB|  
for(int i=0;i<nStartPos.length;i++) %i;r]z-  
{ {JCSR2BB  
nStartPos = input.readLong(); W@R$' r,@O  
nEndPos = input.readLong(); g(ZeFOn  
} jydp4ek_n  
input.close(); 2U-#0,ll]  
} p.6$w:eV  
catch(IOException e){e.printStackTrace ();} Y\ #.EVz  
catch(Exception e){e.printStackTrace ();} i{Y=!r5r  
} Z!q2F%02FO  
Z"teZ0H  
*+_fP|cv  
private void processErrorCode(int nErrorCode) ;t.SiA  
{ QO1A976o  
System.err.println("Error Code : " + nErrorCode); hNu>s  
} dSA [3V  
WZ-4^WM=!  
r[C3u[  
//停止文件下载 F{a0X0ru~  
public void siteStop() jKY Aid{-  
{ *7:u-}c!  
bStop = true; l8hvq(,{  
for(int i=0;i<nStartPos.length;i++) MEdIw#P.}{  
fileSplitterFetch.splitterStop(); 0 .6X{kO  
P#vv+]/  
3B!&ow<rt  
} a'*5PaXU@/  
} ZuF4N=;  
//负责部分文件的抓取 ECmHy@(  
**FileSplitterFetch.java >oM9~7f  
*/ =]5DYRhX]  
package NetFox; y]~+`9  
S0Rf>Eo4  
G#9o?  
import java.io.*; ?3B t ;<^  
import java.net.*; a<a&6 3  
Lz#$_Am'H  
`Yo -5h  
public class FileSplitterFetch extends Thread { ?<>,XyY  
} K+Q9<~u  
hJ$C%1;  
String sURL; //File URL {kRDegby  
long nStartPos; //File Snippet Start Position  1pYmtr  
long nEndPos; //File Snippet End Position 0`g}(}'L  
int nThreadID; //Thread's ID `JY>v io  
boolean bDownOver = false; //Downing is over bJG!)3cx  
boolean bStop = false; //Stop identical b]tA2~e  
FileAccessI fileAccessI = null; //File Access interface ]ut-wqb{p  
o3\SO  
u~naVX\3b  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~vjr;a(B  
{ 82Z[eo  
this.sURL = sURL; _.Z&<.lJ  
this.nStartPos = nStart; <'o'H  
this.nEndPos = nEnd; T}b( M*E  
nThreadID = id; :?&WKW  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 PJSDY1T  
} &}L36|A:  
Eezlx9b  
\M'bY:  
public void run() m_r@t*  
{ k^'d@1z;C  
while(nStartPos < nEndPos && !bStop) gN!E*@7  
{ :#Ex3H7  
Im' :sJ31  
*$4A|EA V  
try{ mvL0F%\.\  
URL url = new URL(sURL); +s*l#'Q  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N,sqrk]  
httpConnection.setRequestProperty("User-Agent","NetFox"); H8o%H=I%  
String sProperty = "bytes="+nStartPos+"-"; 8 /RfNGY  
httpConnection.setRequestProperty("RANGE",sProperty); >2/wzsW  
Utility.log(sProperty); WO+?gu  
#<WyId(  
<De3mZb  
InputStream input = httpConnection.getInputStream(); cciAMQhA  
//logResponseHead(httpConnection); 0c\|S>g [  
6ljRV)  
ELkOrV~a{:  
byte[] b = new byte[1024]; 0]2B-o"kI  
int nRead; LBbo.KxAe3  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $@:>7Y"  
{ ]` &[Se d  
nStartPos += fileAccessI.write(b,0,nRead); E^EU+})Ujr  
//if(nThreadID == 1) ;*37ta  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q_T?G e  
} :)+@qxTy  
} {gWTp  
oZ*=7u  
Utility.log("Thread " + nThreadID + " is over!"); ffoo^1}1  
bDownOver = true; }Nd`;d  
//nPos = fileAccessI.write (b,0,nRead); Q 2SSJ  
} n[MIa]dK  
catch(Exception e){e.printStackTrace ();} o,''f_tRQ|  
} $jm>tW&;  
} ^b|Nw:  
=Zb"T5E  
$E9daUt8"J  
//打印回应的头信息 ad3z]dUZ9  
public void logResponseHead(HttpURLConnection con) q$u\ q.  
{ beHCEwh  
for(int i=1;;i++) G(|(y=ck  
{ bh;b` 5  
String header=con.getHeaderFieldKey(i); xn x1`|1u  
if(header!=null) ]\9B?W(#  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); OL ]T+6X  
Utility.log(header+" : "+con.getHeaderField(header)); SFk11  
else ,TfI  
break; M\.T 0M_  
} +'&_V011<  
} Y5A~iGp8E  
,C'w(af@}  
W|-N>,G  
public void splitterStop() W1vAK  
{ p`l[cVQ<  
bStop = true; \,cKt_{ u  
} J%O4IcE  
RzY`^A6G6  
m|cWX"#g  
} m9<[bEO<$  
w<F;&' ;@h  
'B<qG<>  
/* 8hdAXWPn  
**FileAccess.java {@K2WB  
*//文件访问(定位,写) xMfv&q=k@  
package NetFox; 6`5 @E\"E  
import java.io.*; #ZnX6=;X  
vhquHy.qi#  
Q"K>ML>0  
public class FileAccessI implements Serializable{ ) }it,<  
J0*]6oD!  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Nec(^|[   
RandomAccessFile oSavedFile; ~ ew**@N  
long nPos; !9<RWNKV)Y  
=!P?/  
g /@yK  
public FileAccessI() throws IOException UG?C=Tf  
{ 5@Lxbe( q  
this("",0); 0) Um W{  
} VU0tyj$  
J)yy}[Fx  
lbuW*)  
public FileAccessI(String sName,long nPos) throws IOException =UKR<@QrK  
{ .gkPG'm[  
oSavedFile = new RandomAccessFile(sName,"rw"); AoOG[to7  
this.nPos = nPos; SnF[mN'  
oSavedFile.seek(nPos); _Il9s#NA%  
} 6r-n6#=  
3w:Z4]J  
jUR #  
public synchronized int write(byte[] b,int nStart,int nLen) Z2j*%/  
{ A"3&EuvU  
int n = -1; \NQ)Po@z  
try{ g Wv+i/,  
oSavedFile.write(b,nStart,nLen); [QqNsco)  
n = nLen; Q]g4gj  
} GxDF7 z%&  
catch(IOException e) ?nSp?m;  
{ NUnc"@  
e.printStackTrace (); @)'@LF1Z  
} F)iG D~  
 nIDsCu=A  
>/`c mNmb  
return n; bq&S?! =s  
} 68GGS`&  
dUtIAh-j  
-Tkd@  
} Y&!]I84]  
898wZ{9  
9-iB?a7{.  
/* E!~2\qKT  
**SiteInfoBean.java &b6@_C9  
*/ eF;1l<<   
package NetFox; b`|MK4M(  
Tl7:}X<?  
t7+Ic  
public class SiteInfoBean { '=5_u  
5 /jY=/0.a  
yGG\[I;7  
private String sSiteURL; //Site's URL v*fc5"3eO  
private String sFilePath; //Saved File's Path ~_j%nJ &2  
private String sFileName; //Saved File's Name 59Q Q_#>  
private int nSplitter; //Count of Splited Downloading File 32|L $o  
$H@)hY8wA  
p'!,F; xX  
public SiteInfoBean() <07W&`Dw  
{//nSplitter的缺省值为5 sr@XumT  
//default value of nSplitter is 5 ^W[`##,{Od  
this("","","",5); 4-rI4A<  
} L{,7(C=  
j=QR*8*  
GhQ`{iJM  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) kDP^[V P+  
{ 5{/Pn%5  
sSiteURL= sURL; .-~% w  
sFilePath = sPath; $#JVI:  
sFileName = sName; *]{I\rX  
this.nSplitter = nSpiltter; 78J .~v/  
<\>ak7m  
RYJc>  
} SVWSO  
L=w Fo^N  
rkc%S5we  
public String getSSiteURL() 54cgX)E[x  
{ sH,)e'0  
return sSiteURL; {ZEXlNPww  
} Dlf=N$BL7d  
iwjl--)@K  
5qfKV&D  
public void setSSiteURL(String value) 9l_?n@   
{ (C|V-}/*m  
sSiteURL = value; "<$vU_  
} t}+c/ C%b=  
oqHm:u ^2  
M &EJFpc*  
public String getSFilePath() HF[%/Tu  
{ >P"/ nS"nn  
return sFilePath; x2c*k$<p  
} A?k,}~  
'wlP`7&Tn  
+9rbQ? '  
public void setSFilePath(String value) >t2)Z|1  
{ -vfu0XI~  
sFilePath = value; f_2^PF>?  
} 5nqdY*  
PlRs- %d  
Sz@?%PnU|  
public String getSFileName() k#NMD4(%O  
{ cD@lor j  
return sFileName; Y8'_5?+ 0  
} QjN3j*@  
IMrOPwjc  
[y;ZbfMP|o  
public void setSFileName(String value) (MiOrzT  
{ -mo ' $1  
sFileName = value; %)ov,p |  
} T\CQ  
WREGRy  
(`/i1#nR  
public int getNSplitter() Z@O e}\.$  
{ 6v)eM=   
return nSplitter; `|?$; )  
} @7 HBXP  
\J&#C(pn  
:Zo2@8@7  
public void setNSplitter(int nCount) 5MU@g*gj,C  
{ *<QL[qyV  
nSplitter = nCount; 9sU,.T  
} l<_mag/j9o  
} '6J$X-  
Eakjsk  
H4A+Dg,  
/* 3zF7V:XH  
**Utility.java S9+gVR8]C  
*/ Dq 4}VkY  
package NetFox; J&1N8Wk)  
xi=uXxl  
2]f.mq_PD  
public class Utility { 2+cicBD  
lS*.?4zX  
m?G+#k;K  
public Utility() uxiX"0)g>  
{ o;I86dI6C  
iGNKf|8{  
9gayu<J  
} IFoN<<7/2$  
oioN0EuDk  
//线程睡眠 Ps4A B#3  
public static void sleep(int nSecond) `&7? +s  
{ ]r5Xp#q2  
try{ wk/U"@lq  
Thread.sleep(nSecond); Q[tz)99~  
} 0LuY"(LR  
catch(Exception e) S^=/}PT'  
{ 30`H Xv@  
e.printStackTrace (); m]pvJJ@  
} <QLj6#d7Y  
} Y %8QFM  
RM$S|y{L  
//日志 me\)JCZpb{  
public static void log(String sMsg) 5*Iz3vTq  
{ ')~HOCBSE  
System.err.println(sMsg); s5#g[}dj  
} 824%]i3  
:$d3a"]  
T,@7giQg@  
public static void log(int sMsg) 0_izTke  
{ y%Ah"UY  
System.err.println(sMsg); -q|M=6gOs  
} c3-bn #  
} Gl1$W=pR:  
5|z[%x~f  
$7g(-W  
/* ^@eCT}p{  
**TestMethod.java zxHfQ(  
*/ Y :BrAa[  
package NetFox; 24l9/v'  
K*RRbtb  
FQ^uX]<3j  
public class TestMethod { ^S$w,  
5OE?;PJ(  
:7*\|2zA  
public TestMethod() r${a S@F  
{ ///xx/weblogic60b2_win.exe ^r$5];n  
try{ $yJfAR  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ga%77t|jm3  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q"uu&JC  
SiteFileFetch fileFetch = new SiteFileFetch(bean); aW5~z^I  
fileFetch.start(); i?9Lf  
} Pw1H) <X  
catch(Exception e){e.printStackTrace ();} IA^DfdZY  
-7Wmq[L /  
0Z(b/fdS  
} VlvDodV  
ypVr"fWB  
e@Y R/I8my  
public static void main(String[] args) dq&d>f1  
{ GrIdQi^8  
new TestMethod(); _: x$"i  
} e&nw&9vo  
} ),|bP`V  
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:
10+5=?,请输入中文答案:十五