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
  • 10928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
/* >p2v"XX  
**SiteFileFetch.java mpK|I|-   
*/ /8J2,8vZ  
package NetFox; =@w};e#D  
import java.io.*; T JLz^%t  
import java.net.*; 8t0i j  
pl|< g9  
 //K]zu  
public class SiteFileFetch extends Thread { E(8O3*=  
\ 1ys2BX  
qt/"$6]%  
SiteInfoBean siteInfoBean = null; //文件信息Bean |'Ve75 W6u  
long[] nStartPos; //开始位置 lT1*e(I  
long[] nEndPos; //结束位置 B>YrDJUN  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 !OC?3W:^_  
long nFileLength; //文件长度 QBai;p{  
boolean bFirst = true; //是否第一次取文件 LvhF@%(9J  
boolean bStop = false; //停止标志 lt5~rH2  
File tmpFile; //文件下载的临时信息 nb(#;3DQ  
DataOutputStream output; //输出到文件的输出流 D-~HJ  
;( VJZ_  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) *N< 22w  
public SiteFileFetch(SiteInfoBean bean) throws IOException !i#;P9K  
{ ctH`71Y  
siteInfoBean = bean; }^)M)8zS  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); dRas9g  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Kgk9p`C(  
if(tmpFile.exists ()) 0y2iS' t  
{ ;l}TUo  
bFirst = false; XW5r@:e  
read_nPos(); k. px  
} c>=[|F{{e  
else ~`8`kk8  
{ 9QWS[E4  
nStartPos = new long[bean.getNSplitter()]; k NK)mE  
nEndPos = new long[bean.getNSplitter()]; Tet,mzVuu  
} JF24~Q4P  
fvN2]@:  
7}TjOWC  
E83{4A4  
} /$+ifiFT  
)v0m7L v#/  
'DRyOJnr  
public void run() rf^1%Zo:  
{ ]>*Z 1g;  
//获得文件长度 7NoB   
//分割文件 F0Rk[GM  
//实例FileSplitterFetch QJ>+!p*  
//启动FileSplitterFetch线程 [A[vR7&S  
//等待子线程返回 tw\/1wa.  
try{ YX@[z 5*  
if(bFirst) a;([L8^7$l  
{ Y 1LE.{  
nFileLength = getFileSize(); M)Ogb '@#  
if(nFileLength == -1) Tx],- U  
{ f u\M2"e  
System.err.println("File Length is not known!"); 9J0m  
} y*|"!FK  
else if(nFileLength == -2) (Cqhk:F  
{ }$81FSKh  
System.err.println("File is not access!"); 8Qek![3^  
} 6W#M[0  
else v:s~Y  
{ ;]vE"Mx$  
for(int i=0;i<nStartPos.length;i++) b~%(5r.  
{ !XzRV?Ih;  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 0j_`7<,:  
} G#3 O^,m  
for(int i=0;i<nEndPos.length-1;i++) a&wl-  
{ z9'ME   
nEndPos = nStartPos[i+1]; a:v&pj+|<  
} 3QU<vdtr  
nEndPos[nEndPos.length-1] = nFileLength; ^5j9WV  
} oT%~)g  
} w+*Jl}&\  
b!ot%uZZ  
1i#M(u_  
//启动子线程 | u7vY/  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ZU7,=B=  
for(int i=0;i<nStartPos.length;i++) "P"~/<:)  
{ |4ONGU*`E  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J=| fxR  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "qR qEpD%  
nStartPos,nEndPos,i); ![{>f6{J  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j01#Wq_\fk  
fileSplitterFetch.start(); 1[:?oEI  
} jrZM  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yA \C3r'  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); V!a\:%#^Y  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _l{G Hz  
nEndPos = " + nFileLength); 50uNgLs  
// fileSplitterFetch[nPos.length-1].start(); Ef:.)!;jy  
]k " j  
x.xfMM2n  
//等待子线程结束 egK,e?~  
//int count = 0; s(r(! FZ  
//是否结束while循环 <p-R{}8  
boolean breakWhile = false; ~4`LOROC  
XGbtmmQG  
^<.mUaP  
while(!bStop) OB>Pk_eQK  
{ :,]V 03  
write_nPos(); Ky|dRbK,  
Utility.sleep(500); {^1D|y  
breakWhile = true; D42Bm&JocO  
{%)bxk6  
$*\[I{Zau}  
for(int i=0;i<nStartPos.length;i++) @M?;~M?B]J  
{ $NWXn,Y'  
if(!fileSplitterFetch.bDownOver) vxzh|uF  
{ nX7{09  
breakWhile = false; Dny5X.8  
break; ts<5%{M(  
} ^dJ/>?1  
} #tRLvOR:  
if(breakWhile) kid3@  
break; 4. 7m*  
%V%*0S|U  
\25Rq/&w  
//count++; BA4qQCS;5  
//if(count>4) EC<g7_0F  
// siteStop(); m}54yo  
} PO%Z.ol9  
suC]  
"94e-Nx  
System.err.println("文件下载结束!"); xc7Wk&{=  
} sgW*0o  
catch(Exception e){e.printStackTrace ();} bS=aFl#  
} -aK_  
t :B~P,r  
u[5*RTE  
//获得文件长度 ~Gx"gK0  
public long getFileSize() 2Dgulx5kGZ  
{ ~>2@55wElp  
int nFileLength = -1; 1S/KT4  
try{ %C^U?m`  
URL url = new URL(siteInfoBean.getSSiteURL()); P1tc*2Z  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D/[(}o(  
httpConnection.setRequestProperty("User-Agent","NetFox"); dtD)VNkBZ  
6c>cq\~E  
p_pI=_:  
int responseCode=httpConnection.getResponseCode(); SEu1M}+E  
if(responseCode>=400) n]c6nX:'  
{ /UtCJMQ  
processErrorCode(responseCode); Z.TYi~d/9D  
return -2; //-2 represent access is error ye !}hm=w  
} //T1e7)  
8@ y@}  
N.R,[K  
String sHeader; LE#ko2#ke  
g$$i WC!S<  
s~(!m. R  
for(int i=1;;i++) oRH ]67(Z  
{ l-4+{6lz  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,tqMMBwC~_  
//Utility.log(in.readLine()); wtlIyE  
sHeader=httpConnection.getHeaderFieldKey(i); J=v" HeVm  
if(sHeader!=null)  |e49F  
{ a k&G=a6^  
if(sHeader.equals("Content-Length")) %N``EnF2  
{ `P/7Mf  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); R <Mvwu  
break; ^I2+$  
} 3 ,;;C(  
} +$_.${uwV  
else J" :R,w`  
break; sv}k_6XgY  
} R)}ab{A  
} 4I&e_b< 30  
catch(IOException e){e.printStackTrace ();} %#7NCdk;S  
catch(Exception e){e.printStackTrace ();} pYXusS7S  
8['8ctX  
vq(ElXTO  
Utility.log(nFileLength); G!Gbg3:4e5  
FZdZGK  
2GRL`.1  
return nFileLength; xcf`i:\  
} _c:}i\8R  
1^R[kaY  
) H HBf<  
//保存下载信息(文件指针位置) _'OXrT#Q  
private void write_nPos()  AW[_k%  
{ IhRWa|{I  
try{ <d`ksZ+  
output = new DataOutputStream(new FileOutputStream(tmpFile)); L_ &`  
output.writeInt(nStartPos.length); ,\".|m1o.  
for(int i=0;i<nStartPos.length;i++) nogdOGo  
{ CRpMpPi@}  
// output.writeLong(nPos); {`KRr:w  
output.writeLong(fileSplitterFetch.nStartPos); E$8 D^Zt  
output.writeLong(fileSplitterFetch.nEndPos); JSf \ApX  
} (-e*xM m  
output.close(); VyF|d? b  
} BNj@~uC{  
catch(IOException e){e.printStackTrace ();} &-e@Et`Pg  
catch(Exception e){e.printStackTrace ();} =PQMd  
} )fGIe rS  
()\=(n!J  
655OL)|cD6  
//读取保存的下载信息(文件指针位置) ]i)g!J8f-  
private void read_nPos() 16cc9%   
{ O/{X:Ja{  
try{ vGST{Lz;  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @)^|U"  
int nCount = input.readInt(); O~udlVn<6  
nStartPos = new long[nCount]; e]!`Cl-f80  
nEndPos = new long[nCount]; Kn#CIFbBN  
for(int i=0;i<nStartPos.length;i++) VnU/_# n  
{ 1+Z@4;fk  
nStartPos = input.readLong(); kWZ@v+Mk3  
nEndPos = input.readLong(); *mVQN1  
} V1]QuQ{&s  
input.close(); gXb * zt2  
} %@ ,! (  
catch(IOException e){e.printStackTrace ();} (\zxiK  
catch(Exception e){e.printStackTrace ();} z&Kh$ $)[  
} 6o cTQ}=  
S}}L& _  
FpYeuH%  
private void processErrorCode(int nErrorCode) Hl*V i3bQU  
{ s~tZN  
System.err.println("Error Code : " + nErrorCode); d"nms\=p  
} {yCE>F\  
q L-Ni  
E=&":I6O  
//停止文件下载 \b6vu^;p  
public void siteStop() %8hx3N8>  
{ N2Q b+  
bStop = true; x1'4njTV$  
for(int i=0;i<nStartPos.length;i++) S0]JeP+3!  
fileSplitterFetch.splitterStop(); gK_#R]  
&VdKL2  
}9*NEU) o  
} x T{s%wE  
} #!>QXiyR  
//负责部分文件的抓取 1x3>XN]a  
**FileSplitterFetch.java FE4P EBXvu  
*/ \<kQ::o1y  
package NetFox; 9 .3?$(  
m> YjV>5  
/DGEI&}&:u  
import java.io.*; XbYST%| .  
import java.net.*; |Ca %dg9$@  
H9Dw#.em  
4%"Df1 U  
public class FileSplitterFetch extends Thread { mXK7y.9\  
Zk<Y+!  
v"8i2+j  
String sURL; //File URL pp1kcrE\M  
long nStartPos; //File Snippet Start Position &j!q9F  
long nEndPos; //File Snippet End Position *OU&`\bmE  
int nThreadID; //Thread's ID ?atHZLF  
boolean bDownOver = false; //Downing is over \L:+k `  
boolean bStop = false; //Stop identical )>r sX)  
FileAccessI fileAccessI = null; //File Access interface V: P   
,UATT]>  
3,dIW*<**  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException fb_q2p} G  
{ -40s  
this.sURL = sURL; @E%f AC  
this.nStartPos = nStart; 0kxe5*-|  
this.nEndPos = nEnd; /:+MUw7~  
nThreadID = id; 8umW>  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;9)A+bD]  
} dCO7"/IHW  
Nf1&UgX  
<uXQT$@?  
public void run() 9ohO-t$XkY  
{ V1 {'d[E*  
while(nStartPos < nEndPos && !bStop) 6e4A| <  
{ ur JR[$p  
q?=_{oH9  
"VI2--%v3  
try{ (Nn)_caVb  
URL url = new URL(sURL); (5efNugc  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (&oT6Ji  
httpConnection.setRequestProperty("User-Agent","NetFox"); Ch7&9NW  
String sProperty = "bytes="+nStartPos+"-"; Np>0c -S  
httpConnection.setRequestProperty("RANGE",sProperty); 0ra+MQBg  
Utility.log(sProperty); K/|qn)  
Y8Z-m (OQ  
}cd-BW  
InputStream input = httpConnection.getInputStream(); Wf>=^ ~`  
//logResponseHead(httpConnection); %+ur41HM  
P.'$L\  
}ZkGH}K_}  
byte[] b = new byte[1024]; Ie'iAY  
int nRead; IIUTo  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) drd5o Z  
{ 8 _|"+Ze  
nStartPos += fileAccessI.write(b,0,nRead); TF-a 1z  
//if(nThreadID == 1) Oi$$vjs2  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z2god 1"  
} WlRaD%Q  
mL3 Q  
*ez7Q   
Utility.log("Thread " + nThreadID + " is over!"); UjcKvF  
bDownOver = true; (tz fyZ M  
//nPos = fileAccessI.write (b,0,nRead); {IT;g9x  
} by* v($  
catch(Exception e){e.printStackTrace ();} /9(8ML#E  
} *(j -jbA  
} D~r{(u~Ya  
!= u S  
j\TS:F^z  
//打印回应的头信息 e|Mw9DIW  
public void logResponseHead(HttpURLConnection con) 2X|nPhNi  
{ _v +At;Y  
for(int i=1;;i++) w02t9vz  
{ 7 ^n{BsN  
String header=con.getHeaderFieldKey(i); eZ;DNZK av  
if(header!=null) &d i=alvv1  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); QI{<q<  
Utility.log(header+" : "+con.getHeaderField(header)); @+(a{%~7y  
else 6M X4h  
break; kd+tD!:F(  
} 8e}8@[h  
} %\?Gzc_  
&~sk7iGi  
ZY-mUg  
public void splitterStop() '~OKt`SfIo  
{ &T[BS;  
bStop = true; w$FN(BfA  
} ;ksxz  
_Rey~]iJJ8  
*D;VZs0O  
} LAPC L&Z  
Mp)|5<%  
QliP9-im3  
/* ]-tAgNzl%  
**FileAccess.java @ )m9#F  
*//文件访问(定位,写) Fa A7m  
package NetFox; V9<CeTl'  
import java.io.*; kJ:zMVN  
[Se0+\,&  
jG~UyzWH;  
public class FileAccessI implements Serializable{ ?,Zc{   
ybgAyJ{J<  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 W.VyH|?  
RandomAccessFile oSavedFile; :R9 DJh\  
long nPos; "Go)t + -  
+Y|HO[  
jj*e.t:F  
public FileAccessI() throws IOException NJTC+`Hm  
{ 32ae? d  
this("",0); 6N]V.;0_5  
} +)7Yqh#$  
ufWd) Q  
5 ,1q%  
public FileAccessI(String sName,long nPos) throws IOException .3*VkAs  
{ =| M[JPr  
oSavedFile = new RandomAccessFile(sName,"rw"); A1nEp0%Y  
this.nPos = nPos; )XAD#GYM  
oSavedFile.seek(nPos); Il9pL~u  
} 4Iou| H  
2e @zd\  
7Vxe]s  
public synchronized int write(byte[] b,int nStart,int nLen) ua!g}m~  
{ IRW%*W#  
int n = -1; Uv"GG: K_  
try{ xr\wOQ*`  
oSavedFile.write(b,nStart,nLen);  >o"3:/3  
n = nLen; 34P5[j!h  
} qg;f h]j%  
catch(IOException e) Y8yRQ zu  
{ "x$RTuWA9  
e.printStackTrace (); $@blP<I  
}  ^"d!(npw  
);.q:"  
e!(0y)*  
return n; zu Jl #3YP  
} t"@: a Y"  
\4.U.pKY  
Eb<iR)e H=  
} F+@E6I'g  
K$..#]\TM  
"A_W U|  
/* $LF  
**SiteInfoBean.java hL,+wJ+A  
*/ sgn,]3AUq  
package NetFox; 6_wf $(im  
icf[.  
syYg, G[  
public class SiteInfoBean { !m#cneV  
Gd~Xvw,u  
AVR9G^ce_  
private String sSiteURL; //Site's URL %8T:rS  
private String sFilePath; //Saved File's Path "kKIVlC  
private String sFileName; //Saved File's Name rZy38Wo  
private int nSplitter; //Count of Splited Downloading File "b!QE2bRO  
SrN;S kS  
g]V}azLr  
public SiteInfoBean() 1@Bq-2OD4  
{//nSplitter的缺省值为5 ?'K}bmdt}.  
//default value of nSplitter is 5 0C}7=_?  
this("","","",5); MO :##C  
} QK\QvU2y  
}B_n}<tjD  
.e2u)YqA  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?r QMOJR  
{ ,sk;|OAI  
sSiteURL= sURL; '?5=j1  
sFilePath = sPath; *0y+=,"QU  
sFileName = sName; ? kew[oZ  
this.nSplitter = nSpiltter; 6-#f1D 6  
qoMYiF}/e  
DFs J}` $  
} yg "u^*r&  
Etj*3/n|  
A^JeB<, 5a  
public String getSSiteURL() <>f  
{ M%:ACLYP  
return sSiteURL; ' %OQd?MhL  
} }VE[W  
O!z H5  
e+=Ojo#  
public void setSSiteURL(String value) kRskeMr:Rd  
{ qqSk*oH~  
sSiteURL = value; T IPb ]  
} uG3t%CmN  
pN&Dpz^  
g!7/iKj:  
public String getSFilePath() DT(A~U<y  
{ v|jBRKU99  
return sFilePath; E`>-+~ZUsk  
} 9p(s FQ [  
.*D~ .!  
E/(:\Cm^  
public void setSFilePath(String value) KS'? DO  
{ 4D[W;4/p  
sFilePath = value; -) $$4<L  
} zb~!> QIz{  
/bVU^vo  
S8<O$^L^  
public String getSFileName() _=j0Y=/IF  
{ bR49(K$~  
return sFileName; ^Ebaq`{V\'  
} x!MYIaZ7  
of8/~VO  
UBi0 /  
public void setSFileName(String value) +|Xx=1_?BK  
{ rayC1#f  
sFileName = value; ?bQ~ +M\  
} Az6f I*yP  
_7]* 5Pxo  
j* g5f  
public int getNSplitter() WU{G_Fqaz  
{ $~50M5&K#  
return nSplitter; Oh~J yrZy  
} bKmR &  
v%= G~kF}[  
.!,T> :R  
public void setNSplitter(int nCount) e0+N1kY  
{ A"#Gg7]tl'  
nSplitter = nCount; n'1pNL:  
} 28LjQ!  
} <y\>[7Y  
L$l'wz  
G*mk 19Z  
/* {Aj}s3v  
**Utility.java !tmY_[\  
*/ Dx/?0F7V  
package NetFox; lz faW-nu  
zOCru2/  
-JaC~v(0  
public class Utility { tV@!jaj\  
7 \!t/<  
C* b!E:  
public Utility() zy8W8h(?  
{ +I5@Gys  
eL#pS=  
,S2D/Y^>  
} H{E223  
d5\w'@Di  
//线程睡眠 c@~\ FUr  
public static void sleep(int nSecond) 7z)Hq./3@  
{ BE:HO^-.1  
try{ ; GRSe  
Thread.sleep(nSecond); #)tt}GX  
} 7*M+bZ`x  
catch(Exception e) ckBcwIXlP&  
{ 8U*}D~%!  
e.printStackTrace (); siZw-.  
} X.}:gU-  
} O2us+DhQ  
lSUEE0V%Q  
//日志 J p!Q2}  
public static void log(String sMsg) g599Lc&  
{ vkOCyi?c  
System.err.println(sMsg); x}i:nLhL  
} \&`S~cV9  
H.hF`n  
>>Z.]  
public static void log(int sMsg) T'  %TMA  
{ |#LU"D  
System.err.println(sMsg); GP<A v1  
} 9sFZs]uM  
} G}&B{Ir  
e]'ui<`  
6x^#|;e>lI  
/* y-)|u:~h  
**TestMethod.java &{]zL  
*/ HbX>::J8  
package NetFox; ^J< I Ia4  
WOrz7x  
)AEJ` xC  
public class TestMethod { G?jKm_`L  
PF2PMEBx!  
*R m>bLI  
public TestMethod() 75u/'0~5  
{ ///xx/weblogic60b2_win.exe D kl4 ^}  
try{ JQj?+PI  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4%LGP h  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); WolkW:(Cg  
SiteFileFetch fileFetch = new SiteFileFetch(bean); :Gsh  
fileFetch.start(); [KLs} ~H  
} `|P fa  
catch(Exception e){e.printStackTrace ();}  5f(yF  
SpU+y|\[0  
Wl/oun~o  
} 7+0Kg'^+n  
c3W9"  
y4PR&^l?g  
public static void main(String[] args) 'c*Q/C;  
{ ~,WG284  
new TestMethod(); qT$;ZV #  
} Aw~ =U!  
} rU=qr&f"B  
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