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
  • 9117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
/* zTBr<:  
**SiteFileFetch.java Rk56H  
*/ ;Aiuy{<  
package NetFox; X^#48*"a  
import java.io.*; R>Fie5?  
import java.net.*; Q2PY( #  
8HdmG{7.  
Ooz+V;#Q  
public class SiteFileFetch extends Thread { QP)-O*+AA  
BD[XP`[{  
(1fE^KF@f  
SiteInfoBean siteInfoBean = null; //文件信息Bean G5E03xvL  
long[] nStartPos; //开始位置 JJq= {;  
long[] nEndPos; //结束位置 ;_M .(8L  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 n[CESo%[  
long nFileLength; //文件长度 p-UACMN& c  
boolean bFirst = true; //是否第一次取文件 W+&ZYN 'E  
boolean bStop = false; //停止标志 Vp\BNq_!s  
File tmpFile; //文件下载的临时信息 =U!'v X d  
DataOutputStream output; //输出到文件的输出流 CN\SxK`,  
xZjD(e'  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) |Rw0$he  
public SiteFileFetch(SiteInfoBean bean) throws IOException fzRzkn:=  
{ tQbDP!,A*=  
siteInfoBean = bean; ?C//UN;  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ||cG/I&,  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); P*T 'R  
if(tmpFile.exists ()) Q1IN@Db}y  
{ z)=D&\HX  
bFirst = false; /OK.n3Tt  
read_nPos(); R:x4j#(  
} *Eu ca~%=  
else `&b 8wF  
{ V"*|`z)  
nStartPos = new long[bean.getNSplitter()];  W *0XV  
nEndPos = new long[bean.getNSplitter()]; `UMv#-Y8  
} $[}31=0  
X{o.mN  
Am%zEt$c  
Zaf].R  
} yJc<;Qx  
a Umcs!@  
AtYe\_9$C  
public void run() RD_&m?d  
{ 6*gMG3  
//获得文件长度 C;}~C:aJ  
//分割文件 !`hjvJryw  
//实例FileSplitterFetch E:T<mI?d  
//启动FileSplitterFetch线程 {N[IjY  
//等待子线程返回 ~4'e)g.hG  
try{ >,Zjlkh3  
if(bFirst) C,hs!v6  
{ uJA8PfbD  
nFileLength = getFileSize(); }k.-xaj  
if(nFileLength == -1) LpeQx\  
{ &OK(6o2m;  
System.err.println("File Length is not known!"); #+|{l*>  
} !>Db  
else if(nFileLength == -2) SfyZ,0  
{ )TFaG[tj  
System.err.println("File is not access!"); f ySzZ  
} hf^,  
else VmHok  
{ m ,,-rC  
for(int i=0;i<nStartPos.length;i++) 2B3H -`  
{ ~dC)EG  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); )7Gm<r  
} 3_~V(a  
for(int i=0;i<nEndPos.length-1;i++) s[NkPh9&  
{ Oj\lg2Ck  
nEndPos = nStartPos[i+1]; #Z)e]4{!l  
} D'ZR>@w@  
nEndPos[nEndPos.length-1] = nFileLength; hU3c;6]3  
} [0El z@.C  
} 6C4c.+S  
a&6 3[p.<}  
AIR,XlD  
//启动子线程 U8-#W(tRR  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /jaTH_Q),:  
for(int i=0;i<nStartPos.length;i++) |Nd!+zE$Z  
{ G)]'>m<y  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K>l$Y#x}k  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), & V^ Z  
nStartPos,nEndPos,i); H)}>&Z4  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cKdn3 2Y4  
fileSplitterFetch.start(); rE;*MqYt&  
} yhJH3<  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F$ShhZgi  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); V$VqYy9 *  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?>cx; "xF  
nEndPos = " + nFileLength); q,F\8M\$  
// fileSplitterFetch[nPos.length-1].start(); ri1D*CS  
zR6,?Tzg  
>0Y >T6!  
//等待子线程结束 x :\+{-  
//int count = 0; -;20|US)u  
//是否结束while循环 ? [l[y$9  
boolean breakWhile = false; .LhIB?  
u)Y~+ [Q  
BCYTlxC'  
while(!bStop) %i{Z@  
{ Qn(2UO!pD  
write_nPos(); 9Bvi2 3  
Utility.sleep(500); zflfV!vAg  
breakWhile = true; ztTj2M"  
]W~\%`#8?  
-KhNsUQk  
for(int i=0;i<nStartPos.length;i++) z0+LD  
{ E;/WP!/.  
if(!fileSplitterFetch.bDownOver) H?*EQK`7?0  
{ u,AP$+Qk  
breakWhile = false; B(7oHj.i2  
break; 6=U81  
} DDQ}&`s  
} JFH3)Q  
if(breakWhile) C-E~z{  
break; )' +" y~  
~U(`XvR\4  
3O7]~5 j1  
//count++; pYf57u  
//if(count>4) -0r 0M )  
// siteStop(); k#uSH eq7f  
} dv -L!C  
M<^]Ywq*p  
p.6C.2q~s]  
System.err.println("文件下载结束!"); 5xC4lT/U  
} s!,m,l[P  
catch(Exception e){e.printStackTrace ();} uNCM,J!#~  
} /4/'&tY  
.Ds d Q4Y  
+Ac.@!X}%  
//获得文件长度 ~k\Dde  
public long getFileSize() WJWi'|C4  
{ k-IL%+U  
int nFileLength = -1; .2"-N5Z  
try{ m:B9~ lbT+  
URL url = new URL(siteInfoBean.getSSiteURL()); ${m;x:'  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V5:ad  
httpConnection.setRequestProperty("User-Agent","NetFox"); yJQ>u  
OL]P(HRm]~  
VzfaUAIZl  
int responseCode=httpConnection.getResponseCode(); h ` qlI1]  
if(responseCode>=400) 0t*e#,y  
{ \c}_!.xj"  
processErrorCode(responseCode); K8#MQR2@  
return -2; //-2 represent access is error k%uR!cL  
} [As9&]Bv5  
W*S}^6ZT`  
"| Oj!&0  
String sHeader; pHQrjEF*  
"Vh3hnS~  
p3r("\Za,  
for(int i=1;;i++) GsIVx!  
{ >[}lC7 z,  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R !g'zS'  
//Utility.log(in.readLine()); GWFF.Mo^  
sHeader=httpConnection.getHeaderFieldKey(i); `_aX>fw  
if(sHeader!=null) ICck 0S!  
{ G0#<SJ,)  
if(sHeader.equals("Content-Length")) SU ,G0.  
{ !LI6_Oq  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); JfD-CoQS'  
break; wcH,!;3z+  
} }uZ/^_U.  
} aeZ$Wu>]W  
else ')N[)&&Q{  
break; 1WjNFi  
} Zt_~Zxn3  
} "<Ozoo1&w  
catch(IOException e){e.printStackTrace ();} L4O.=*P1  
catch(Exception e){e.printStackTrace ();} r{ >Q{$Q  
UE9RrfdN  
#[ f]-c(!  
Utility.log(nFileLength); :eIi^K z[  
<fHJ9(5$V  
7 Tb[sc'  
return nFileLength; ^'9.VVyz  
} w*?SGW  
dG&^M ".(  
>{6U1ft):  
//保存下载信息(文件指针位置) ~c,CngeL0  
private void write_nPos() nuKcq!L  
{ Gj_7wP$  
try{ m)7Ql!l  
output = new DataOutputStream(new FileOutputStream(tmpFile)); vB74r]'F  
output.writeInt(nStartPos.length); !3F3E8%  
for(int i=0;i<nStartPos.length;i++) Su/8P[q_  
{ (1EtC{ m  
// output.writeLong(nPos); 6VUs:iO1j5  
output.writeLong(fileSplitterFetch.nStartPos); ZnKjU ]m  
output.writeLong(fileSplitterFetch.nEndPos); IG+g7kDCY  
} s\+| ql  
output.close(); mT:NC'b<9  
} GP>\3@>  
catch(IOException e){e.printStackTrace ();} ;b{yu|  
catch(Exception e){e.printStackTrace ();} SzP`(}AU  
} NSawD.9mV  
!"2S'oQKS  
oyB gF\  
//读取保存的下载信息(文件指针位置) }y%c.  
private void read_nPos() J>l?HK  
{ apOXcZ   
try{ xKR\w!+Z'  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &(7=NAQsE  
int nCount = input.readInt(); dI%?uk  
nStartPos = new long[nCount]; +0}z3T1L  
nEndPos = new long[nCount]; SR$ 'JGfp  
for(int i=0;i<nStartPos.length;i++) _aeIK  
{ t4iD<{4  
nStartPos = input.readLong(); [rkw k\m*  
nEndPos = input.readLong(); li hIPMU  
} @)\4 $#+-  
input.close(); nb<e<>L  
} u,V_j|(e  
catch(IOException e){e.printStackTrace ();} T;G<62`.h  
catch(Exception e){e.printStackTrace ();} {J1iheuS}  
} %afN&T  
hkb&]XWi[  
9tX+n{i  
private void processErrorCode(int nErrorCode) Zg$S% 1(Q  
{ i;rcg d  
System.err.println("Error Code : " + nErrorCode); )I#{\^  
} mC0_rN^Aj  
-"NK"nb  
#c!rx%8I  
//停止文件下载 Oa2\\I  
public void siteStop() zuu<;^/R  
{ -Bl]RpHCe  
bStop = true; l A%FS]vh  
for(int i=0;i<nStartPos.length;i++) X n8&&w"  
fileSplitterFetch.splitterStop(); jDb"|l  
Jz}`-fU`  
VKkvf"X  
} QM![tZt%;  
} o\F>K'  
//负责部分文件的抓取 a:8 MoH4  
**FileSplitterFetch.java Bn9#F#F<  
*/ m]vS"AdX  
package NetFox; m/Erw"Z  
hq&|   
"~=-Q#xO  
import java.io.*; Nm !~h|3  
import java.net.*; [YP{%1*RM  
[GPCd@  
NVghkd  
public class FileSplitterFetch extends Thread { CY*o"@-o5)  
DK eB%k  
^2H;  
String sURL; //File URL dB6['z)2  
long nStartPos; //File Snippet Start Position tKS[  
long nEndPos; //File Snippet End Position _RzF h  
int nThreadID; //Thread's ID n$`+03a  
boolean bDownOver = false; //Downing is over | p!($  
boolean bStop = false; //Stop identical ufCpX>lNF  
FileAccessI fileAccessI = null; //File Access interface e!PB3I  
%ufh  
NT0n [o^  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]J[d8S5  
{ .X qeO@z  
this.sURL = sURL; 81"` B2  
this.nStartPos = nStart;  =n5n  
this.nEndPos = nEnd; _Dd>e=v  
nThreadID = id; 5F+G8  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m~ 5"q%;  
} cF 4,dnI  
aZ$5"  
Y0.'u{J*  
public void run()  z3]W #  
{ }tw+8YWkz  
while(nStartPos < nEndPos && !bStop) u7^(?"x  
{ ;W+8X-B  
P3`$4p?  
0PqI^|!  
try{ qEuO@oE  
URL url = new URL(sURL); s;YbZ*oaMe  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {1Y @%e  
httpConnection.setRequestProperty("User-Agent","NetFox");  od{\z  
String sProperty = "bytes="+nStartPos+"-"; 0 zK{)HZ  
httpConnection.setRequestProperty("RANGE",sProperty); q8&l%-d`  
Utility.log(sProperty); xu_,0 ZT]{  
'B{FRK  
[al$sCD]+  
InputStream input = httpConnection.getInputStream(); A+!,{G  
//logResponseHead(httpConnection); r88De=*  
`<yQ`Y_X  
Cdib{y<ji  
byte[] b = new byte[1024]; L-}J=n\  
int nRead; 5wmd[YL  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~5`oNa  
{ 5?F5xiW  
nStartPos += fileAccessI.write(b,0,nRead); ^P^%Q)QXl  
//if(nThreadID == 1) e*qGrg(E  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -&sY*(:n_  
} t))MZw&@  
;:j1FOj  
HO['o{>BL  
Utility.log("Thread " + nThreadID + " is over!"); hO&b\#@~  
bDownOver = true; CxeW5qc  
//nPos = fileAccessI.write (b,0,nRead); `:Gzjngc  
} JC%&d1  
catch(Exception e){e.printStackTrace ();} 4MS#`E7LrC  
} s :7/\h  
} h Fik>B#!  
0W}qp?  
9M;t4Um  
//打印回应的头信息 RSe4 lw  
public void logResponseHead(HttpURLConnection con) (z>t4(%\  
{ R?O)v Lmd  
for(int i=1;;i++) 6IG?t  
{ Kc?4q=7q  
String header=con.getHeaderFieldKey(i); ^L5-2;s<U'  
if(header!=null) 3q}j"x?  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fCx (  
Utility.log(header+" : "+con.getHeaderField(header)); + x=)Kp>  
else t|eH'"N%o  
break; _ Lb"yug  
} gr*CN<  
} '"fJA/O  
q6)fP4MQ]  
kFwFPK%B  
public void splitterStop() _%- +"3Ll  
{ !CWe1Dm  
bStop = true; 5K ;E*s,  
} 29,ET}~  
IGcq*mR=  
s@ r{TXEn  
} s{Y4wvQyB  
'1:)q  
 vUJ; D  
/* 8Rwk o6x  
**FileAccess.java u*G<?  
*//文件访问(定位,写) a&x:_vv  
package NetFox; )^ Y+Vn  
import java.io.*; X n$ZA-  
R,G*]/r`  
qU7_%Z  
public class FileAccessI implements Serializable{ iCF},W+  
Y@0'0   
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 SOhM6/ID2/  
RandomAccessFile oSavedFile; e4YP$}_L  
long nPos; )&c#?wx'w  
:rUMmO-  
L"|Bm{Run  
public FileAccessI() throws IOException X`KSj N&(  
{ 3NtUB;!  
this("",0); cx$IWQf2  
} ]a4U\yr  
M_};J;  
cdt9hH`Cd  
public FileAccessI(String sName,long nPos) throws IOException l,7& z  
{ p0bWzIH  
oSavedFile = new RandomAccessFile(sName,"rw"); ZOqS"3j! j  
this.nPos = nPos; x%=CEe?6  
oSavedFile.seek(nPos); FAEF  
} ]8\I{LR  
8u+kA mI  
N s+g9+<A  
public synchronized int write(byte[] b,int nStart,int nLen) g0tnt)]  
{ Nnl3r@  
int n = -1; YpDJ(61+  
try{ z6iKIw $  
oSavedFile.write(b,nStart,nLen); 25)9R^  
n = nLen; TC?B_;a  
} P9bM+@5e  
catch(IOException e) $V(]z`b&  
{ TU0-L35P1  
e.printStackTrace (); D=-}&w_T"  
} #[#evlr=  
jW\:+Taq  
AU$~Ap*rsa  
return n; [yXmnrxA  
} f1MRmp-f'  
TVD~Ix  
`F7]M  
} =\oH= f  
}tW-l*\U  
%+(AKZu:  
/* t]LiFpy2IC  
**SiteInfoBean.java a:)FWdp?9  
*/ R ZY=c  
package NetFox;  vmqa_gU\  
@'R)$:I%L  
{Yj5Mj|#  
public class SiteInfoBean { N `|A  
'Rn-SD~gIr  
EL?(D  
private String sSiteURL; //Site's URL 'QCIKCn<  
private String sFilePath; //Saved File's Path :5NMgR.d  
private String sFileName; //Saved File's Name /I`TN5~  
private int nSplitter; //Count of Splited Downloading File 6h;(b2p{  
8)X9abC  
c* {6T}VZr  
public SiteInfoBean() zuvPV{ X  
{//nSplitter的缺省值为5 tK%ie\  
//default value of nSplitter is 5 fjRVYOG#  
this("","","",5); OUv<a `0  
} pLB2! +  
UCLM*`M  
1INX#qTZ  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) z'q~%1t  
{ S}@7Z`  
sSiteURL= sURL; NKO"'   
sFilePath = sPath; }`"}eN @,  
sFileName = sName; 0^ODJ7  
this.nSplitter = nSpiltter; fu "cX;  
kamQZzPe  
 )d2Z g  
} 1B~O!']N<  
>v:ex(y0  
ra$:ibLN  
public String getSSiteURL() PJ.\ )oP  
{ E]@&<TFq  
return sSiteURL; +F; 2FD$  
} Cr5ND\  
v~nKO?{   
E\[BE<y  
public void setSSiteURL(String value) 3oCI1>k  
{ o1.~g'!^  
sSiteURL = value; ${ {4L ?7  
} +U o NJ   
o<Zlm)"%1  
*)Rm X$v3  
public String getSFilePath() ;kgP:n  
{ 2)f_L|o,m  
return sFilePath; _?c.m*)A  
} VgH O&vU  
,;g%/6X  
P@7>R7gS  
public void setSFilePath(String value) <0CjEsAB]  
{ rnIj pc F  
sFilePath = value; #A/OGi  
} ")Fd'&58  
-r\jIO_  
>yO/p(/;jR  
public String getSFileName() {iD/0q  
{ <]rayUyaf  
return sFileName; l/N<'T_G  
} NL9.J @"b  
?v2_7x&  
/q9I^ztV  
public void setSFileName(String value) gu k,GF9p]  
{ 5|H;%T 3_  
sFileName = value; ,!:c6F+  
} UleT9 [M  
$BwWQ?lp  
hi8q?4jE  
public int getNSplitter() c!Hz'W  
{ Bz]tKJ  
return nSplitter; <o(;~  
} t<!m4Yd|#  
fd)8lK[KJ"  
R]"Zv'M(AM  
public void setNSplitter(int nCount) qezWfR`  
{ 6Og@tho  
nSplitter = nCount; (?qCtLZ  
} A0{xt*g   
} t!?`2Z5  
uMcI'=  
'm`O34h  
/* '.|}  
**Utility.java `^)`J  
*/ Ik:G5m<ta  
package NetFox; `c Gks  
I-#!mFl  
u+)!C*ho  
public class Utility { mY 1l2  
=Vg~ VD   
yq~  
public Utility() r^,_m,s'<  
{ b<u\THy#  
eb_.@.a  
.}dLqw  
} /uw@o9`~2-  
j7P49{  
//线程睡眠 QV[&2&&^<<  
public static void sleep(int nSecond) yX&# rI  
{ D2ggFxqe  
try{ a ,mgM&yD  
Thread.sleep(nSecond); ?_]Y8f  
} wkt4vE87  
catch(Exception e) Zo=,!@q(  
{ Ab$E@H #  
e.printStackTrace (); )q$[uS_1[  
} eXl?f_9  
} #(] D]f[@  
r]e{~v/  
//日志 2zj` H9  
public static void log(String sMsg) SzLlJUVX  
{ HYl+xH'.j  
System.err.println(sMsg); %pZT3dcK  
} "@x( 2(Y&  
i;HXz`vT7  
WyV4p  
public static void log(int sMsg) *JOK8[Qn  
{ I"]E}nd)  
System.err.println(sMsg); KDN#CU  
} L4iWR/&  
} ?c.\\2>|F  
H VM %B{(  
I(6%'s2  
/* /qQx~doK  
**TestMethod.java '&CZ%&(Gw  
*/ i3 js'?7E  
package NetFox; Dk\%,[4(  
IQBL;=.J.  
:lu!%p<$  
public class TestMethod { B} qRz  
(CQ! &Z8  
m]DP{-s4  
public TestMethod() {JWixbA  
{ ///xx/weblogic60b2_win.exe T)tr"<F5NP  
try{ Q}&'1J  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); yK{P%oh)  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); RlfI]uCDM  
SiteFileFetch fileFetch = new SiteFileFetch(bean); {r&r^!K;  
fileFetch.start(); Nr@,In|JS  
} CX#d  
catch(Exception e){e.printStackTrace ();} !d##q)D f?  
$Y/z+ea  
0+0 Y$;<  
} nu^@}|UG  
y95  #t  
/8Lb_QH{  
public static void main(String[] args) .Z 7t E?  
{ GUQ3XF\  
new TestMethod(); ,5 ,r .  
} []OS p&  
} Va[&~lA)  
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
如果您在写长篇帖子又不马上发表,建议存为草稿
认证码:
验证问题:
10+5=?,请输入中文答案:十五