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
  • 9127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
/* BbXU| QtY  
**SiteFileFetch.java $d2kHT  
*/ yxG:\y b  
package NetFox; 8_<&f%/  
import java.io.*; esh$*)1  
import java.net.*; u 5Eo  
^x_ >r6  
;zZ,3pl-E  
public class SiteFileFetch extends Thread { ovQS ET18b  
>w2Q 1!  
(zS2Ndp  
SiteInfoBean siteInfoBean = null; //文件信息Bean N /sEec  
long[] nStartPos; //开始位置 O>SuZ>g+7  
long[] nEndPos; //结束位置 k(-Z@   
FileSplitterFetch[] fileSplitterFetch; //子线程对象 CQBT::  
long nFileLength; //文件长度 $^vp'^uW>  
boolean bFirst = true; //是否第一次取文件 `i t+D  
boolean bStop = false; //停止标志 Z:UgozdC  
File tmpFile; //文件下载的临时信息 5?3Isw`v2  
DataOutputStream output; //输出到文件的输出流 @)OnIQN~  
cyGN3t9`.  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Tsm1C#6 Y*  
public SiteFileFetch(SiteInfoBean bean) throws IOException JNxW6 cK  
{ 2AXF$YjY  
siteInfoBean = bean; QIij>!c4  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); <TLGfA1bC  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 8S.')<-f  
if(tmpFile.exists ()) ~A[YnJYA#  
{ 8/Et&TJ`  
bFirst = false; 9Qt)m fqM  
read_nPos(); u Q:ut(  
} VD9 q5tt7  
else q)K-vt)98  
{ OH$ F >wO  
nStartPos = new long[bean.getNSplitter()]; eW%L$I  
nEndPos = new long[bean.getNSplitter()]; bK$/,,0=X/  
} JHvFIo   
j<l#qho{h  
[^?13xMb  
UOR _M5  
} }.fL$,7a  
A$9q!Ui#d  
|u^)RB  
public void run() <S\;k@f  
{ wUru1_zjO  
//获得文件长度 Ud>`@2  
//分割文件 ee&nU(pK  
//实例FileSplitterFetch $xRo<,OV+  
//启动FileSplitterFetch线程 ov\Ct%]  
//等待子线程返回 F-$Z,Q]S  
try{ 0M#N=%31  
if(bFirst) dr| | !{\  
{ Y H<$ +U  
nFileLength = getFileSize(); 7XUhJN3n  
if(nFileLength == -1) VFilF<jvu  
{ f![xn2T  
System.err.println("File Length is not known!"); y!7B,  
} ?-pxte8  
else if(nFileLength == -2) Nl~Z,hT$*  
{ U/.w;DI   
System.err.println("File is not access!"); !: m`9o8  
} " t5 +*  
else "2ZIoa!^  
{ qxf+#  
for(int i=0;i<nStartPos.length;i++) Q<RT12|`  
{ 8s QQK.N(  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); **T:eI+  
} /Qr A8  
for(int i=0;i<nEndPos.length-1;i++) 'fS?xDs-v  
{ Rz`@N`U  
nEndPos = nStartPos[i+1]; v\fzO#vj  
} gXq!a|eH  
nEndPos[nEndPos.length-1] = nFileLength; /lf\ E=  
} "%:7j!#X|I  
} g/OI|1a  
NlA*\vco  
Z -pyFK\  
//启动子线程 :6 Uk)   
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ! (B_EM  
for(int i=0;i<nStartPos.length;i++) 536^PcJlN  
{ S8*^ss>?^R  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5+y@ ]5&g  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8BHL  
nStartPos,nEndPos,i); F`fGz)Mk  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,"@w>WL<9  
fileSplitterFetch.start(); Vn)%C_-]A  
} i%xI9BO9  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MP jr_yc]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); IgLVn<5n  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nped  
nEndPos = " + nFileLength); lN);~|IOv7  
// fileSplitterFetch[nPos.length-1].start(); ?$<SCN =  
d-hbvLn  
jVX._bEGX  
//等待子线程结束 s0gJ f[  
//int count = 0; n)tU9@4Np  
//是否结束while循环 B:e.gtM5  
boolean breakWhile = false; vAi"$e  
vz6SCGg,  
86/.8  
while(!bStop) ''_,S,.a20  
{ lxm*;?j`W  
write_nPos(); "=9-i-K9B  
Utility.sleep(500); nARxn#<+  
breakWhile = true; XQK^$Iq]V  
A)OdQFet(  
fG<Dhz@  
for(int i=0;i<nStartPos.length;i++) 9Kc0&?q@D  
{ +VwV5iy[`  
if(!fileSplitterFetch.bDownOver) h{\t*U 54'  
{ D`V6&_. p  
breakWhile = false; +z+ F-  
break; et@">D%;]  
} '^hsH1  
} :]EP@.(  
if(breakWhile) =\M)6"}y}  
break; 3b#L17D3_  
VxNXd?  
aZP 2R"  
//count++; kl| g  
//if(count>4) 3 *G5F}7%=  
// siteStop(); jz|VF,l  
} Cm^Yl p  
HB%K|&!+  
7@JjjV  
System.err.println("文件下载结束!"); 6j_ 678  
} ol50d73B  
catch(Exception e){e.printStackTrace ();} aXC!t  
} B@d1xjp)']  
M/*Bh,M`  
*K`x;r  
//获得文件长度 iM8sX B  
public long getFileSize() Hyf"iYv+  
{ {JXf*IJ  
int nFileLength = -1; kl=xu3j  
try{ D2{L=  
URL url = new URL(siteInfoBean.getSSiteURL()); 2v4W6R  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :RHm*vt  
httpConnection.setRequestProperty("User-Agent","NetFox"); p*Xix%#6  
TFo}\B7  
)GK+  
int responseCode=httpConnection.getResponseCode(); en%J!<&W{K  
if(responseCode>=400) ># INEO  
{ 2bkJ /u`i  
processErrorCode(responseCode); ;r3}g"D@  
return -2; //-2 represent access is error )Q~C4C-j  
} xF&6e&nv  
H*GlWgfG  
: g 5(HH  
String sHeader; N=q#y@L  
<o2,HTWNPS  
{ E^U6@  
for(int i=1;;i++) oI*d/*  
{ *u}'}jC1X  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); '|_/lz$h  
//Utility.log(in.readLine()); MBlBMUJk  
sHeader=httpConnection.getHeaderFieldKey(i); 2R\+}  
if(sHeader!=null) 7"#f!.E  
{ d)\2U{  
if(sHeader.equals("Content-Length")) ,'u*ZB;  
{ >[EBpYi  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >G&^?5  
break; V n^)  
} Zd$JW=KR]l  
} Z4#v~!  
else S.1( 3j*  
break; 7H4L-J3  
} P:qz2Hw  
} nX)f'[ 7  
catch(IOException e){e.printStackTrace ();} g@Ld"5$^2  
catch(Exception e){e.printStackTrace ();} &Bm&i.r  
bf1)M>g,O  
a#$N%=j  
Utility.log(nFileLength); qIz}$%!A  
^,`M0g\$  
S#mK Pi+3  
return nFileLength; H$Kw=kMw  
} C!5I?z&  
MF^_Z3GS'  
RtwUb(wn6  
//保存下载信息(文件指针位置) j|mv+O  
private void write_nPos() !3@{U@*Z]  
{ v$;@0t:;#  
try{ Je 31".  
output = new DataOutputStream(new FileOutputStream(tmpFile)); lY8`5Uz  
output.writeInt(nStartPos.length); g>yry}>04%  
for(int i=0;i<nStartPos.length;i++) cv]BV>=E  
{ Ch t%uzb,  
// output.writeLong(nPos); b4)k&*dfR  
output.writeLong(fileSplitterFetch.nStartPos); O:._W<  
output.writeLong(fileSplitterFetch.nEndPos); )nOE 8y/  
} ctHEEFWm  
output.close(); < <sE`>)  
} #jm@N7OZ  
catch(IOException e){e.printStackTrace ();} m<3w^mww  
catch(Exception e){e.printStackTrace ();} x)_r@l`$ix  
} []gRfM]$&  
2QL?]Vo  
N}DL(-SQ3  
//读取保存的下载信息(文件指针位置) ' Rc#^U*n  
private void read_nPos() or!!s 5[d  
{ e}e6r3faz  
try{ p31oL{D  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); WFem#hq   
int nCount = input.readInt(); 6} #"qqnx  
nStartPos = new long[nCount]; 8ljuc5,J  
nEndPos = new long[nCount]; uFo/s&6K  
for(int i=0;i<nStartPos.length;i++) n[P\*S  
{ `BjR.xMv  
nStartPos = input.readLong(); U <rI!!#9  
nEndPos = input.readLong(); Pj&A=  
} IJ_ m  
input.close(); m]P/if7  
} X$^JAZ09  
catch(IOException e){e.printStackTrace ();} 6OtVaT=}<O  
catch(Exception e){e.printStackTrace ();} {E~Xd  
} /tZ0 |B(  
-?z\5 z  
#1gO?N(<=  
private void processErrorCode(int nErrorCode) ;{gT=,KQ`  
{ 3ev -Iqz  
System.err.println("Error Code : " + nErrorCode); (hN?:q?'  
} #kci=2q_  
Ha)np  
$w/E9EJ)3A  
//停止文件下载 mX;H((  
public void siteStop() R$d7\nBG  
{ |IN[uQ  
bStop = true; 1'fb @vO  
for(int i=0;i<nStartPos.length;i++) QD4:W"i  
fileSplitterFetch.splitterStop(); Du!._  
yLqF ,pvO  
?oKL &I@  
} R5kH0{zM  
} n"Z |e tZ4  
//负责部分文件的抓取 Y{+3}drJE  
**FileSplitterFetch.java &a6,ln:P  
*/ ?Oc -aa  
package NetFox; RG1\=J$:E  
CN\=9Rvs  
O|e}   
import java.io.*; x*q35K^PE  
import java.net.*; V:Mk)8Gf|  
!i Jipe5  
:c:V%0Yji  
public class FileSplitterFetch extends Thread { bLlH//ZRH  
(NaK3_  
F 7LiG9H6`  
String sURL; //File URL t^U^Tr  
long nStartPos; //File Snippet Start Position SiTeB)/  
long nEndPos; //File Snippet End Position R6P\T\~E  
int nThreadID; //Thread's ID BIj   
boolean bDownOver = false; //Downing is over c\K<sM{  
boolean bStop = false; //Stop identical 12OlrU  
FileAccessI fileAccessI = null; //File Access interface ShGp^xVj  
oY.\)eJ~>  
]0-<>  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4Jykos2  
{ QNg\4%  
this.sURL = sURL;  KGT3|)QN  
this.nStartPos = nStart; `eD1|Go9  
this.nEndPos = nEnd; !8/gL  
nThreadID = id; 6$RpV'xz  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !y[3]8Xxv  
} u"Y]P*[k  
8,*3zVk-  
;;Tq$#vd  
public void run() -?fR|[\[U  
{ g~)3WfC$[  
while(nStartPos < nEndPos && !bStop) &*gbK6JB  
{ y-a|Lu*  
E1(1E?}!  
vRr9%zx  
try{ 5@f5S0 Y  
URL url = new URL(sURL); I`^YAbnb  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }-nU3{1  
httpConnection.setRequestProperty("User-Agent","NetFox"); @GeHWv  
String sProperty = "bytes="+nStartPos+"-"; Ep ">v>"  
httpConnection.setRequestProperty("RANGE",sProperty); bV6V02RF  
Utility.log(sProperty); {7X~!e|w  
:<utq|#s  
eaAPKx  
InputStream input = httpConnection.getInputStream(); _#pnjo   
//logResponseHead(httpConnection); h<NRE0-  
8 Z8Y[p  
xS+rHC  
byte[] b = new byte[1024]; ~Z/7pP+  
int nRead; wS$46M<  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >nM%p4E  
{ UA(;fZ@  
nStartPos += fileAccessI.write(b,0,nRead); 28UVDG1?  
//if(nThreadID == 1) mi^hvks<  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S^j,f'2  
} (U9a@ 1  
rQj~[Y.c  
1exfCm  
Utility.log("Thread " + nThreadID + " is over!"); iN)af5)[^  
bDownOver = true; ?,XC =}  
//nPos = fileAccessI.write (b,0,nRead); S#2[%o  
} P%)b+H{$h  
catch(Exception e){e.printStackTrace ();} yL&/m~{s  
} %?=)!;[  
} f#OQ (WTJE  
~:Mm<*lL%  
{ERjeuDm]  
//打印回应的头信息 e{!vNJ0`  
public void logResponseHead(HttpURLConnection con) H(> M   
{  Zi4d]  
for(int i=1;;i++) R|Y~u*D  
{ U ~1 SF  
String header=con.getHeaderFieldKey(i); 8&.-]{Z  
if(header!=null) 7>,rvW:]  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1VLLo~L%  
Utility.log(header+" : "+con.getHeaderField(header)); .'lN4x  
else &HL{LnLP@/  
break; Ef,Cd[]b  
} ~ 5"J(  
} [h HG .  
/s`;9)G]9  
j-32S!  
public void splitterStop() 6?o>{e7n^  
{ Funj!x'uE  
bStop = true; 6K 4+0xXv  
} YoAg  
W4vBf^eC  
RIjM(P  
} ;rHz;]si  
m[8 @Unt  
/aOlYqM(>  
/* SRf5W'4y  
**FileAccess.java H\+-cvl  
*//文件访问(定位,写) !01i%W'  
package NetFox; !<r8~A3!(  
import java.io.*; [H^ X"D  
fl)zQcA  
{D,RU8&  
public class FileAccessI implements Serializable{ l%<c6;  
E}$V2ha0zu  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Z,aGtJ.a'9  
RandomAccessFile oSavedFile; %U?)?iZdL  
long nPos; 7\%$>< K  
]o*$h$?s  
)4ncutb  
public FileAccessI() throws IOException C Z tiWZ  
{ M/B/b<['  
this("",0); &+- e  
} v#Upw\!  
2AK}D%jfc  
#r}uin*jD  
public FileAccessI(String sName,long nPos) throws IOException kqf8=y  
{ $1e pf  
oSavedFile = new RandomAccessFile(sName,"rw"); 6~@5X}^<0  
this.nPos = nPos; os**hFPk;1  
oSavedFile.seek(nPos); O`(U/?   
} EfKntrom[  
-tyaE  
} 07r  
public synchronized int write(byte[] b,int nStart,int nLen) ? s4oDi|:  
{ (8x gn  
int n = -1; U>A6eWhH  
try{ ImHU:iR[J-  
oSavedFile.write(b,nStart,nLen); jL_5]pzJ  
n = nLen; a8QfkOe  
} VDn:SGj5  
catch(IOException e) )7AM3%z1?  
{ <kbnu7?a*  
e.printStackTrace (); q+%!<]7X  
}  MYx88y  
4)nt$fW  
tN!Bvj:C[M  
return n; 3:AU:  
} #Fzb8Yo  
mz-N{>k  
"tX7%(  
} ^ZVO ql&  
~`[8"YUL  
Z s73 ad  
/* w4A#>;Qu*  
**SiteInfoBean.java rKIRNc#d  
*/ 7LdzZS0OM  
package NetFox; fTgbF{?xh  
}4KW@L[g  
'!@A}&]  
public class SiteInfoBean { 8Fx]koP.  
|^!Vo&T  
nx$bM(.  
private String sSiteURL; //Site's URL ?Cc :)  
private String sFilePath; //Saved File's Path }.t^D|  
private String sFileName; //Saved File's Name ^O \q3HA_4  
private int nSplitter; //Count of Splited Downloading File O{BW;Deo  
T 9MzUV&  
#JFYws  
public SiteInfoBean() DaCblX  
{//nSplitter的缺省值为5 0%H24N 9.  
//default value of nSplitter is 5 R8ZD#,;  
this("","","",5); U!NI_uk  
} kQ[Jo%YT?E  
2-7Z(7G{ F  
_.-#E$6s#q  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N'a?wBBR  
{ tWX7dspx/  
sSiteURL= sURL; wPQ&Di*X}  
sFilePath = sPath; ^XNw$@&',  
sFileName = sName; -;ER`Jqs,  
this.nSplitter = nSpiltter; z L8J`W  
h[y*CzG  
e# <4/FR  
} B,MQ.|s[  
P eHW[\)  
C (U  
public String getSSiteURL() AoU_;B\b%  
{ q#m!/wod  
return sSiteURL; J@gm@ jLc  
} "u5KbJW  
$E@ouX?  
0<3E  
public void setSSiteURL(String value) AHWh}~Yi  
{ p9Z ].5Pd"  
sSiteURL = value; BjB&[5?z  
} ,3k@L\$.x  
0}D-KvjyP  
HoL~j({  
public String getSFilePath() []=_<]{  
{ T;J7+0  
return sFilePath; $)f"K  
} l-cW;b~  
s!aO*\[<h  
3l$E8?[Zwi  
public void setSFilePath(String value) y,V6h*x2  
{ 9u?Eb~#$  
sFilePath = value; VZTmzIk.Y  
} R)Q/Ff@o0  
l[Tt[n  
fw:7U %MGv  
public String getSFileName() |SxMN %M!  
{ },v&rkwR  
return sFileName; Enu!u~1]F  
} 'H!V54 \j  
v` $%G  
W oWBs)E  
public void setSFileName(String value) HmW=t}!  
{ brj[c>ID  
sFileName = value; aj?2jU~Pq  
} *|^,DGfQ6  
:q(D(mK  
Ca X^)  
public int getNSplitter() 'OG{*TDPu  
{ JBvk)ogM  
return nSplitter; &jt02+Hj'  
} 1*L^^% w  
3`x sK[  
D$QGLI9(  
public void setNSplitter(int nCount) 3Fgz)*Gu]  
{ )U]:9)   
nSplitter = nCount; %n4@[fG%K  
} &{BBxv)y  
} ?THa5%8f  
> n1h^AW  
[#IBYJ.6  
/* [;*\P\Xih  
**Utility.java 40R"^*  
*/ fjcr<&{:  
package NetFox; Bpm,mp4g\#  
q?(A!1(u  
}M^_Z#|,  
public class Utility { p?}f|mQS)  
z1kBNOr  
hr%U>U9F  
public Utility() )sRN!~  
{ (v]P<3%  
uW ) \,  
4{Q$!O>  
} U7jhV,gO4  
eU`;L [  
//线程睡眠 ]F !'M  
public static void sleep(int nSecond) 3xP~~j;7  
{ u IAZo;  
try{ DQ%`v =  
Thread.sleep(nSecond); c!.=%QY  
} K4_~ruhr  
catch(Exception e) N`f!D>b:dn  
{ c$.UE  
e.printStackTrace (); h|K\z{ A  
} *U :VM'a  
} NS h%t+XU]  
3T"2S[gT  
//日志 P a3{Ds  
public static void log(String sMsg) I+*osk  
{ 0K&_D)  
System.err.println(sMsg); e jP,29  
} BHEs+ e0  
xT:qe  
dUI3erO  
public static void log(int sMsg) 3(aRs?/ O  
{ MgHOj   
System.err.println(sMsg); D% oueW  
} bh{E&1sLh  
} <_=JMA5  
G}182"#4  
KrJ5"1=  
/* #c6ui0E%;t  
**TestMethod.java lq~Gc M  
*/ T@B"BoKU  
package NetFox; 7We?P,A\;  
f$Gr`d  
JtSuD>H`"  
public class TestMethod { c]GQU  
Lc58lV=  
&,^mM' C  
public TestMethod() u wH)$Pl  
{ ///xx/weblogic60b2_win.exe c'"#q)  
try{ qsD?dHi7  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !>CE(;E>z  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V+Y|4Y&  
SiteFileFetch fileFetch = new SiteFileFetch(bean); R 4DM_ u  
fileFetch.start(); d&/^34gn  
} )C'G2RV  
catch(Exception e){e.printStackTrace ();} ` 52% XI  
=9kj? u~  
kTr6{9L  
} OD{5m(JwL  
PthId aN@  
;7;zhJs1t  
public static void main(String[] args) ?lu_}t]  
{ ,lrYl!,  
new TestMethod(); kEp.0wL'  
} X(4s;i  
} <E D8"~_  
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