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
  • 8610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
/* "4LYqDe  
**SiteFileFetch.java ]*pALT6  
*/ 65RWaz;|  
package NetFox; MpM-xz~  
import java.io.*; VAc-RaA  
import java.net.*; g% :Q86u  
GmN} +(  
FqiC zP4  
public class SiteFileFetch extends Thread { w}<BO> z  
\LRno3  
A>^\jIB>  
SiteInfoBean siteInfoBean = null; //文件信息Bean ]%(hZZ  
long[] nStartPos; //开始位置 :|oH11 y  
long[] nEndPos; //结束位置 >`8r52  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 s4lkhoN\t  
long nFileLength; //文件长度 \$s<G|<P  
boolean bFirst = true; //是否第一次取文件 Py6c=&*  
boolean bStop = false; //停止标志 Zi/l.=9n  
File tmpFile; //文件下载的临时信息 0@1AH<  
DataOutputStream output; //输出到文件的输出流 q@P5c  
wo84V!"A  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) bT>% *  
public SiteFileFetch(SiteInfoBean bean) throws IOException 8QDRlF:;<  
{ \`r5tQr  
siteInfoBean = bean; BCF- lrZ&  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); a3 wUB  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); aT"q}UTK  
if(tmpFile.exists ()) = LuH:VM&  
{  N\DEY]  
bFirst = false; GAbX.9[V  
read_nPos(); v')Fq[H  
} t#oY|G3O}  
else $k*E^~qT  
{ !l@IG C  
nStartPos = new long[bean.getNSplitter()]; '=@O]7o~  
nEndPos = new long[bean.getNSplitter()]; {) 4D1  
} A[v]^pv'  
lRnst-inlI  
2t\a/QE)E  
QvK/31*QG  
} V{;Mh u`+  
+Tde#T&[  
BBnbXhxZ  
public void run() * 4G J<  
{ /<s'@!W  
//获得文件长度 #\iQ`Q<B  
//分割文件  Yul-.X  
//实例FileSplitterFetch @DfjeS)u^  
//启动FileSplitterFetch线程 Bm"jf]  
//等待子线程返回 +"Ek? )?  
try{ nX<!n\J T  
if(bFirst) dx}()i\@  
{ $zbm!._~DA  
nFileLength = getFileSize(); j/wG0~<kz  
if(nFileLength == -1) \dCoY0Z ;  
{ iN5~@8jAzz  
System.err.println("File Length is not known!"); eI8^T?  
} Qs8iu`'  
else if(nFileLength == -2) 5 |{0|mP  
{ e2UbeP  
System.err.println("File is not access!"); Ps7(4%  
} "EF: +gi#"  
else A1Mr  
{ wx BQ#OE  
for(int i=0;i<nStartPos.length;i++) ^o,Hu#  
{ qS>P,>C  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); SQWwxFJ  
} EU TTeFp  
for(int i=0;i<nEndPos.length-1;i++) [oKc<o7)~"  
{ k uU,7 <o  
nEndPos = nStartPos[i+1]; ,d<wEB?\`  
} /!oi`8D  
nEndPos[nEndPos.length-1] = nFileLength; N \[Cuh8Fe  
} Pe!uk4}w  
} d"uR1 rTk  
CT3wd?)z`  
]plg@  
//启动子线程 T/MbEqAf  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :,y V?E6]  
for(int i=0;i<nStartPos.length;i++) q0jzng  
{ W@AZ<(RI:  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G+ Y`65  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),  :D} xT]  
nStartPos,nEndPos,i); V /$qD  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8V`r*:\  
fileSplitterFetch.start(); Yq4_ss'nB  
} }E[S%W[  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a"EP`  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7=u\D  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", R0_%M  
nEndPos = " + nFileLength); ;n00kel$  
// fileSplitterFetch[nPos.length-1].start(); X8<<;?L  
s{x2RDAt  
 r75,mX  
//等待子线程结束 {6~v oVkj  
//int count = 0; [IF3 ,C  
//是否结束while循环 ;gTdiwfgZ=  
boolean breakWhile = false; <tMiI)0%  
sKB])mf]  
|L.QIr,jCC  
while(!bStop) `Q<hL{AH  
{ ? Sj,HLo@U  
write_nPos(); BC%t[H} >R  
Utility.sleep(500); _OZrH(8  
breakWhile = true; ' ]l,  
~A}"s-Kq5  
.d^8w97  
for(int i=0;i<nStartPos.length;i++) &sh %]o8  
{ ox{)O/aj  
if(!fileSplitterFetch.bDownOver) o>311(:  
{ Q*ZqY  
breakWhile = false; Z9cch- u~  
break; @ T'!;)  
} Dh BUMDoB  
} K;,n?Q w  
if(breakWhile) h<4WY#Y  
break; SWY?0Pu  
A/lxXy}D  
 [53rSr  
//count++; F +D2 xN@  
//if(count>4) `LVItP(GUM  
// siteStop(); pi q%b]  
} {vx{Hwyv  
aDm$^yP  
z ,87;4-  
System.err.println("文件下载结束!"); }N#jA yp!  
} j0>S)Q  
catch(Exception e){e.printStackTrace ();} I5wf|wB-  
} _]E"hr6a  
K8XXO"  
;}#tm9S;  
//获得文件长度 ]t\fw'  
public long getFileSize() xqmP/1=NO  
{ Xnt`7L<L  
int nFileLength = -1; zq80}5%2CT  
try{ RvZi%)  
URL url = new URL(siteInfoBean.getSSiteURL()); 7h<B:~(K  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b&"=W9(V  
httpConnection.setRequestProperty("User-Agent","NetFox"); BLgmF E2  
>7!4o9)c  
B%6>2S=E  
int responseCode=httpConnection.getResponseCode(); T-xcd  
if(responseCode>=400) pR4{}=g,  
{ <,(6*b  
processErrorCode(responseCode); X<Rh-1$8F  
return -2; //-2 represent access is error 4};iL)  
} Y\(Q  
q{ n~v>wU  
0\qbJ  
String sHeader; w1KLQd:yq  
z2i?7)(?;A  
Fx~=mYU  
for(int i=1;;i++) cR 4xy26s  
{ W( E!:  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); f]^(|*6  
//Utility.log(in.readLine()); 6k%N\!_TUW  
sHeader=httpConnection.getHeaderFieldKey(i); F[ N{7C3  
if(sHeader!=null) W @Y$!V<  
{ \S[:  
if(sHeader.equals("Content-Length")) j/TsHJ=  
{ -Mb nYs)  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?5K.#>{  
break; FTI[YR8?Y  
} rV<yM$IA  
} 2P`hdg  
else 36` aG Y  
break; |eAl!k  
}  :J`:Q3@  
} l}j5EWe  
catch(IOException e){e.printStackTrace ();} oZHsCQ%  
catch(Exception e){e.printStackTrace ();} SouPk/-B80  
@aN<nd`q)  
n7i;^=9 mM  
Utility.log(nFileLength); .e!dEF)D  
3+u11'0=t  
x$QOOE]  
return nFileLength; ,'v]U@WK  
} @QV|<NeH  
:/c=."z.  
Ytmt+9  
//保存下载信息(文件指针位置) o/@.*Rj>Bg  
private void write_nPos() 'b]GcAL  
{ dms R>Q  
try{ ..UmbJJ.u  
output = new DataOutputStream(new FileOutputStream(tmpFile)); fLA!oeq{&}  
output.writeInt(nStartPos.length); sn '#]yM  
for(int i=0;i<nStartPos.length;i++) +v2Fr}  
{ }_u1'  
// output.writeLong(nPos); &, hhH_W  
output.writeLong(fileSplitterFetch.nStartPos); 5&D)W>{d  
output.writeLong(fileSplitterFetch.nEndPos); (s4w0z  
} %*>=L$A  
output.close(); u7ZSs-LuHw  
} wo5"f}vd#  
catch(IOException e){e.printStackTrace ();} v~[=|_{  
catch(Exception e){e.printStackTrace ();} v3x_8n$C9  
} dqwAQ-x  
|G&<@8O  
\\AufAkJ  
//读取保存的下载信息(文件指针位置) y2gI]A  
private void read_nPos() lO3$V JI  
{ fWhwI+  
try{ xbnx*4o0  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JaoRkl?F  
int nCount = input.readInt(); 5"%r,GMU  
nStartPos = new long[nCount]; I7ZY9W(S  
nEndPos = new long[nCount]; }`E5I&r4  
for(int i=0;i<nStartPos.length;i++) Rx<m+=  
{ {Lwgj7|~  
nStartPos = input.readLong(); `*mctjSN  
nEndPos = input.readLong(); jq yqOhb4  
} *kY\,r&!P  
input.close(); }dX[u`zQ  
} ~McmlJzJG  
catch(IOException e){e.printStackTrace ();} 2>p K  
catch(Exception e){e.printStackTrace ();} 58\Rl  
} bq/ m?;  
PVH^yWi n  
S;sggeP7,  
private void processErrorCode(int nErrorCode) :CH "cbo  
{ >&6pBtC_  
System.err.println("Error Code : " + nErrorCode); ~UA-GWb  
} N3 .!E|  
c"Kl@ [1\~  
DygMavA.  
//停止文件下载 Q*&>Ui[&  
public void siteStop() e` Z;}& ,  
{ .I$ Q3%s  
bStop = true; )XV|D  
for(int i=0;i<nStartPos.length;i++) P +ONQN|  
fileSplitterFetch.splitterStop(); j|gQe .,1  
_U(b  
3TVp oB`  
} B38_1X7  
} bO]^TRaiJ  
//负责部分文件的抓取 #_0OYL`(mE  
**FileSplitterFetch.java (JHzwI8+  
*/ =># S7=  
package NetFox; c ]M!4.  
?$i`K|  
f4YcZyBGv  
import java.io.*; ,~u5SR  
import java.net.*; F$<>JEdX  
l5_RG,O0A  
! 7A _UA8  
public class FileSplitterFetch extends Thread { T;K@3]FbX  
E/2kX3}  
O32p8AxEz  
String sURL; //File URL (jd)sf6Tj[  
long nStartPos; //File Snippet Start Position JJ`RF   
long nEndPos; //File Snippet End Position J}U);A  
int nThreadID; //Thread's ID ;#$ 67G$  
boolean bDownOver = false; //Downing is over H&\[iZ| -N  
boolean bStop = false; //Stop identical 1Z%^U ?  
FileAccessI fileAccessI = null; //File Access interface 6$$4!R-  
0NrUB  
soh)IfZ  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @yiAi:v@  
{ H~IR:WOw  
this.sURL = sURL; {:BAh 5e|  
this.nStartPos = nStart; Y '7f"W  
this.nEndPos = nEnd; lVF}G[B  
nThreadID = id; "#1KO1@G  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 e/hA>  
} f'&30lF  
Br^4N9  
tS#=I.ET  
public void run() C#{s[l\]  
{ nAIV]9RAZ%  
while(nStartPos < nEndPos && !bStop) 1bjhEO W  
{ "P.H  
Z Ear~  
gZ vX~  
try{ ~Sy/q]4ys*  
URL url = new URL(sURL); 5-'jYp/  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P`r@<cgb=  
httpConnection.setRequestProperty("User-Agent","NetFox"); #tX\m ;  
String sProperty = "bytes="+nStartPos+"-"; iR} 3 [  
httpConnection.setRequestProperty("RANGE",sProperty); _`3'D`s  
Utility.log(sProperty); ;[@);-9q  
q)0?aL  
4)MKYhm  
InputStream input = httpConnection.getInputStream(); =)_9GO  
//logResponseHead(httpConnection); v0uDL7  
-OV:y],-  
IIrh|>d_7  
byte[] b = new byte[1024]; ?pSb,kN}'  
int nRead; eaLR-+vEB  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) RhwqAok|lj  
{ U8TH}9Q  
nStartPos += fileAccessI.write(b,0,nRead); U9^o"vT  
//if(nThreadID == 1) BkywYCWZ )  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |dNJx<-  
} FvpaU\D  
]^aOYtKX  
/zxLnT; 5  
Utility.log("Thread " + nThreadID + " is over!"); dJyf.VJ  
bDownOver = true; X*f#S:kiNU  
//nPos = fileAccessI.write (b,0,nRead); 6zv-nMZc  
} 6&,n\EXF  
catch(Exception e){e.printStackTrace ();} me-Tv7WL  
} .Ukejx  
} | e{F;8  
 l Ozi|  
zgre&BV0q  
//打印回应的头信息 obA}SF  
public void logResponseHead(HttpURLConnection con) Cka&b  
{ .*N]SbU<8  
for(int i=1;;i++) t!}QG"ma  
{ #?=?<"*j  
String header=con.getHeaderFieldKey(i); yTt,/+I%gJ  
if(header!=null) q8&2M  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); j"G1D-S:  
Utility.log(header+" : "+con.getHeaderField(header)); 2cv!85  
else g-G;8x'n  
break; \3nu &8d  
} ":=\ ci]e%  
} RNa59b  
(41BUX  
GD*rTtDWn  
public void splitterStop() ]M^ k~Xa  
{ i/Zv@GF  
bStop = true; vbFi# |EU  
} ,Sz`$'^c  
\tv^],^`  
tc-pVw:TV  
} t<8vgdD  
Oz8"s4Y7  
TpnJm%9`)t  
/* </xz V<Pi  
**FileAccess.java K|n%8hRy  
*//文件访问(定位,写) #fB&Hv #s7  
package NetFox; U(xN}Y ?  
import java.io.*; RLy2d'DS  
VTS7K2lBvX  
y $i^C:N  
public class FileAccessI implements Serializable{ 0)<\jo1 F  
WY>r9+A?W  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q,Oj  
RandomAccessFile oSavedFile; 7TDt2:;]  
long nPos; R'Gka1v  
VkFvV><"  
FYwMmb ~3  
public FileAccessI() throws IOException  Tt;h?  
{ \xCI8 *W  
this("",0); JAt$WW{  
} Rs$fNW@P  
8|]r>L$Wk  
o7 :~C]  
public FileAccessI(String sName,long nPos) throws IOException RN, 5>.w  
{ ShP&ss  
oSavedFile = new RandomAccessFile(sName,"rw"); X283.?  
this.nPos = nPos; &^q!,7.J  
oSavedFile.seek(nPos); c:*[HO\  
} [ADSGnw  
9_=0:GH k  
aNt+;M7g`  
public synchronized int write(byte[] b,int nStart,int nLen) 4*`AYx(  
{ MWGs:tpL4  
int n = -1; Z--A:D>  
try{ d+caGpaR  
oSavedFile.write(b,nStart,nLen); 9\dpJ\  
n = nLen; R #f*QXv  
} n'?AZ4&z  
catch(IOException e) EWb'#+BP  
{ k<&zVV '  
e.printStackTrace (); XY_hTHJ  
} <w,NMu"  
dnwTD\),  
Etj0k} A  
return n; j ."L=  
} Ee~<PDzB  
biLNR"/E  
+6zW(Ql/  
} k?bIu  
y 4 wV]1  
"V= IG{.  
/* I ~U1vtgp  
**SiteInfoBean.java )7aUDsu>4  
*/ *\-$.w)k  
package NetFox; CI#6 r8u  
JJQS7,vG  
QLPb5{>KDS  
public class SiteInfoBean {  iH`Q4  
*dAQ{E(rO  
*XU2%"Sc  
private String sSiteURL; //Site's URL N1',`L5  
private String sFilePath; //Saved File's Path X_3*DqY  
private String sFileName; //Saved File's Name -n:~m p  
private int nSplitter; //Count of Splited Downloading File AT:L&~O.  
i?3~Gog  
"  jBc5*  
public SiteInfoBean() u?Uu>9@Z  
{//nSplitter的缺省值为5 )X2 /_3  
//default value of nSplitter is 5 jW8,}Xs  
this("","","",5); ?lPn{oB9"  
} `MLOf  
]Pp}=hcD  
p{vGc-zP .  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _Xqa_6+/  
{ '5)PYjMnH  
sSiteURL= sURL; m{w'&\T  
sFilePath = sPath; BNw};.lO  
sFileName = sName; f 0|wN\  
this.nSplitter = nSpiltter; ?~:4O}5Ax  
uGc0Lv4i/  
1PN!1=F}  
} 3|0wD:Dy  
`;}w!U  
^\f1zg9I  
public String getSSiteURL() hNRN`\5Z  
{ mXPA1#qo  
return sSiteURL; \[J\I  
} 5r` x\  
p9y@5z  
Bjp4:;Bb  
public void setSSiteURL(String value) `DFo:w!k  
{ 5%jy7)8C  
sSiteURL = value; n~Yr`5+Z  
} rj ] ~g  
$~,J8?)(z  
2CF5qn}T  
public String getSFilePath() U^;|as  
{ )z_5I (?&  
return sFilePath; <\'aUfF v  
} QPyHos `  
dJ 9v/k_  
Y6[ O s1  
public void setSFilePath(String value) m S4N%Q  
{ /8? u2 q  
sFilePath = value; h J H  
} LTTMxiq[*  
edL sn>\*#  
,Dy9-o  
public String getSFileName() 6pdek3pOCt  
{ m ##_U9O  
return sFileName; _B?Hw[cc  
} re x MS  
A7I{Le  
;U&~tpd  
public void setSFileName(String value) B; ^1W{%J  
{ vNQ|tmn  
sFileName = value; .O&[9`"'  
} xdgbs-a)  
'!"rE1e  
2w;Cw~<=d  
public int getNSplitter() .Q!pQ"5  
{ s>I~%+V.?:  
return nSplitter; W) ?s''WE;  
} F|&%Z(@a  
4d8}g25C  
+&4@HHU{G  
public void setNSplitter(int nCount) &U_T1-UR2  
{ mM2DZ^"j(  
nSplitter = nCount; EEP&Y?  
} Od+nBJ   
} jpkKdQX)  
jSQM3+`b  
GQ0(lS  
/* =bOMtQ]  
**Utility.java v@,`(\Ca'  
*/ 8K9RA<  
package NetFox; Ww0dU_  
~^J9v+  
8I7JsCj  
public class Utility { 2<E@f0BVAy  
wWVB'MRXB,  
tkP& =$  
public Utility() [ e#[j{  
{ 6t{G{ ]  
4xF}rm  
cp&1yB   
} ge]Z5E(1  
tP89gN^PA|  
//线程睡眠 }\QXPU{UVd  
public static void sleep(int nSecond) -U{!'e8YiN  
{ ETm:KbS  
try{ ~g}blv0q+B  
Thread.sleep(nSecond); lXRB"z  
} MM*9Q`cB  
catch(Exception e) E <N%  
{ T>irW(  
e.printStackTrace (); +bk+0k9k5  
} 2S//5@~_m  
} sWKv> bx  
kbSl.V%)  
//日志 n] 8*yoge  
public static void log(String sMsg) {S`Rr/E|%  
{ 5R6QZVc  
System.err.println(sMsg); 7#j9"*  
} ,U~in)\ U  
%ed TW[C`  
L>pSE'}  
public static void log(int sMsg) ~i0>[S3 '  
{ O&Y22mu  
System.err.println(sMsg); b_)SMAsO7  
} #n+sbx5~7  
} Of#"nu  
tm.&k6%  
p.5 *`, )  
/* _6->D[dB  
**TestMethod.java ]} pAZd  
*/ :BF WX  
package NetFox; _TyQC1 d  
ZU`HaL$  
I7C+XUQkQ  
public class TestMethod { ,=2)1I]  
dKmPKeJM  
Lr Kx  
public TestMethod() RN$q,f[#  
{ ///xx/weblogic60b2_win.exe MEOfVh  
try{ E O"  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KVHK~Y-G  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1pqYB]*u_  
SiteFileFetch fileFetch = new SiteFileFetch(bean); X*a7`aL  
fileFetch.start(); $#_^uWN-M  
} iZ0.rcQj'o  
catch(Exception e){e.printStackTrace ();} KP!7hJhw  
 nyZ?m  
'i;ofJ[.c  
} 'cY @Dqg1  
I#xhmsF  
Ok phbAX  
public static void main(String[] args) h1#l12k^'  
{ U+ uIuhz  
new TestMethod(); OA7=kH@3c  
} :I^4ILQCD  
} M#yUdl7d  
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