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
  • 8563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
/* I $5*Puy#  
**SiteFileFetch.java u0 & aw  
*/ fe,A\W&8  
package NetFox; $ U~3$*R  
import java.io.*; f;Cu@z{b  
import java.net.*; c= f _  
SfHs,y6  
M@R_t(&=   
public class SiteFileFetch extends Thread { x37pj)i/  
lDBn3U&z>  
*jAw  
SiteInfoBean siteInfoBean = null; //文件信息Bean ue YBD]3'  
long[] nStartPos; //开始位置 >'qkW$-95  
long[] nEndPos; //结束位置 Dg:2*m_!j{  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 p_K` `JE  
long nFileLength; //文件长度 >_ )~"Ra  
boolean bFirst = true; //是否第一次取文件 {e>E4(  
boolean bStop = false; //停止标志  xr }jw  
File tmpFile; //文件下载的临时信息 +N~?_5lv\s  
DataOutputStream output; //输出到文件的输出流 &HS6}  
s :4<wmu4=  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) hM": ?Rx  
public SiteFileFetch(SiteInfoBean bean) throws IOException W0++q=F  
{ z } L3//  
siteInfoBean = bean; \5k^zGF4o  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); j|WuOZm\0  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ISp'4H7R+N  
if(tmpFile.exists ()) X={n9*Sd8  
{ qQL]3qP  
bFirst = false; c(]NpH in  
read_nPos(); !W^b:qjJ  
} !!WSGZUR  
else ^p'iX4M  
{ I eQF+Xz  
nStartPos = new long[bean.getNSplitter()]; {;iG}jK  
nEndPos = new long[bean.getNSplitter()]; Q%x |  
} 3A~53W$M  
n'dxa<F2|  
Pk9 4O  
3IrmDT  
} E0g` xf 6c  
|.]:#)^X?  
x{$~u2|  
public void run() L`fDc  
{ pi'w40!:  
//获得文件长度 >o#5tNm  
//分割文件 T'n~Qf U  
//实例FileSplitterFetch ` 0YI?$G1  
//启动FileSplitterFetch线程 FG?69b>  
//等待子线程返回 RV*7?y%3  
try{ (x.O]8GKP  
if(bFirst) (A6 -9g>  
{ e``X6=rcG  
nFileLength = getFileSize(); xz @/^Cj  
if(nFileLength == -1) p6qza @  
{ h{ &X`$  
System.err.println("File Length is not known!"); "`sr#  
} 0st)/\  
else if(nFileLength == -2) b~M3j&  
{ **zh>Y}6  
System.err.println("File is not access!"); (c{<JYEC  
} rUb`_W@  
else NAy3Zd}  
{ ^'UJ&UfX  
for(int i=0;i<nStartPos.length;i++) B/*`u  
{ :3,aR\  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); z}Qt6na]-  
} i[gq8%  
for(int i=0;i<nEndPos.length-1;i++) fvW7a8k3  
{ gtcU'4~  
nEndPos = nStartPos[i+1]; `%8byy@$  
} =Ws-s f]  
nEndPos[nEndPos.length-1] = nFileLength; mP1EWh|  
} }RGp)OFY&  
} &&N]u e@>  
2>E.Q@c  
i.0}d5Y  
//启动子线程 yJt0KUw@!  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; a<Ru)Q?=  
for(int i=0;i<nStartPos.length;i++) LX4*3c|i,  
{ rPK)=[MZ  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z3ucJH/)V  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5LT{]&`9  
nStartPos,nEndPos,i); EF7Y4lp  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \]uo^@$bm  
fileSplitterFetch.start(); $)L=MEdx  
} g;bfi{8s_  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H.8f-c-4we  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); JN{.-k4Ha  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", g$++\%k&  
nEndPos = " + nFileLength); i+ I%]  
// fileSplitterFetch[nPos.length-1].start(); LuM[*_8  
r ek89.p  
-ejH%CT  
//等待子线程结束 REyk,s2"6  
//int count = 0; @O;gKFx  
//是否结束while循环 {X=gjQ9  
boolean breakWhile = false; qO yg&]7  
P= e3f(M2  
QEl:>HG  
while(!bStop) IF<?TYy=3B  
{ D[.;-4"_  
write_nPos(); >x(3p@6p  
Utility.sleep(500); +V"t't7  
breakWhile = true; 8vhg{L..  
ail%#E8  
&dqC =oK]  
for(int i=0;i<nStartPos.length;i++) 9=(*#gRd  
{ J|DID+M  
if(!fileSplitterFetch.bDownOver) 3y}0J @  
{ k<mfBNvuo  
breakWhile = false; N# Ru `;  
break; 80X #V  
} a$ f$CjQ  
} Kh)SgJ3B@  
if(breakWhile) b%w?YR   
break; [B}$U|V0  
gbP]!d:I  
Ax D&_GT  
//count++; l{:7*U{d  
//if(count>4) uG1)cm B}  
// siteStop(); YlI/~J  
} `0@onDQVc=  
/8Sg<  
B~/:["zTh&  
System.err.println("文件下载结束!"); @M[t|  
} (Rqn)<<2  
catch(Exception e){e.printStackTrace ();} dgLE/r?  
} oDY $F%  
!J3dlUFRO  
qpo3b7(N  
//获得文件长度 ,KXS6:1%5Y  
public long getFileSize() )aW;w|#n  
{ d!+8  
int nFileLength = -1; OH2Xxr[bQ  
try{ N5>ioJj  
URL url = new URL(siteInfoBean.getSSiteURL()); by 'P}  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9oOr-9t3  
httpConnection.setRequestProperty("User-Agent","NetFox"); _*d8:|qw  
`|Aj3a3sND  
))y`q@  
int responseCode=httpConnection.getResponseCode(); [TUy><Z  
if(responseCode>=400) Hw 7   
{ ),9^hJ1+@  
processErrorCode(responseCode); 9#K,@X5 j  
return -2; //-2 represent access is error ?:D#\4=US  
} i:9f#  
.>4Zt'gCt  
`)sC".b7  
String sHeader; W@R\m=e2  
.h!oo;@  
jV83%%e  
for(int i=1;;i++) RR,gC"cTi  
{ -+^E5  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,+0#.N s$  
//Utility.log(in.readLine()); f+#^Lngo  
sHeader=httpConnection.getHeaderFieldKey(i); rkdf htpI  
if(sHeader!=null) *D&(6$[^  
{ W_ w^"'  
if(sHeader.equals("Content-Length")) $a'n{EP  
{ ^gP pmb<x  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,BGaJ|k  
break; A*;I}F  
}  T06BrX  
} 3q{op9_T7  
else [)K?e!c8  
break; El3Y1g3+3  
} \k?Fu=@  
} U?vG?{A  
catch(IOException e){e.printStackTrace ();} T#ktC0W]h  
catch(Exception e){e.printStackTrace ();} `zQ2 i}Uju  
TQXp9juK  
W{pyU \  
Utility.log(nFileLength); +;Yd<~!c Z  
s&T"/4  
.Ux bwTup  
return nFileLength; YVcFCl  
} 5](-(?k}~  
6Vr:?TI7  
G/l 28yt  
//保存下载信息(文件指针位置) [sxJ<  
private void write_nPos() >ZAb9=/M)F  
{ {bQi z  
try{ xa7~{ E,  
output = new DataOutputStream(new FileOutputStream(tmpFile)); A1VbqA  
output.writeInt(nStartPos.length); l/(|rl#6  
for(int i=0;i<nStartPos.length;i++) BSe{HmDq  
{ j2@19YXe@  
// output.writeLong(nPos); /Y NV  
output.writeLong(fileSplitterFetch.nStartPos); ;ps 0wswX  
output.writeLong(fileSplitterFetch.nEndPos); 6N7^`ghTf  
} Ie12d@  
output.close(); %}T' 3  
} 2n/cq K   
catch(IOException e){e.printStackTrace ();} 3aD\J_  
catch(Exception e){e.printStackTrace ();} ]+C;C  
} XTzz/.T;Z  
^0 zWiX  
,hMd xZJd  
//读取保存的下载信息(文件指针位置) 9j[lr${A  
private void read_nPos() dfo_R  
{ w(>mP9Cb  
try{ fdU`+[_  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]UtfI  
int nCount = input.readInt(); /UwB6s(  
nStartPos = new long[nCount]; n U0  
nEndPos = new long[nCount]; -SyQ`V)T7N  
for(int i=0;i<nStartPos.length;i++) # Uc0 W  
{ BWtGeaW/sr  
nStartPos = input.readLong(); U|[+M@F_L  
nEndPos = input.readLong(); #*J+4a w3  
} 2u B66i  
input.close(); V:<NQd  
} 6[\b]I\Q  
catch(IOException e){e.printStackTrace ();} {x&"b-  
catch(Exception e){e.printStackTrace ();} A.f!SYV6  
} ymNL`GYN[  
C rA7lu'  
w+^z{3>  
private void processErrorCode(int nErrorCode) WUEjWJA-MB  
{ fga{ b7  
System.err.println("Error Code : " + nErrorCode); &]d-R  
} a$}n4p  
cJIA/HQe  
dfU z{  
//停止文件下载 CLQE@kF;  
public void siteStop() 7v{X?86&  
{ y<r@zb9  
bStop = true; B#zu< z  
for(int i=0;i<nStartPos.length;i++) EZ  N38T  
fileSplitterFetch.splitterStop(); 0j'H5>m"  
)MV`(/BC*  
oU\Q|mN(  
} y2_^lW%  
} (] Zyk, [  
//负责部分文件的抓取 do-mkvk  
**FileSplitterFetch.java 0=WZ 8|R  
*/ Q!%C:b  
package NetFox; {c#{dT  
8!{;yz  
5.]eF$x2  
import java.io.*; D&)w =qIu  
import java.net.*; |i/Iv  
P&6hk6#  
Q&JnF`*  
public class FileSplitterFetch extends Thread { U]8 @  
@c >a  
o?9k{  
String sURL; //File URL lZ\Si  
long nStartPos; //File Snippet Start Position G!%Cc0d"7  
long nEndPos; //File Snippet End Position nVSuvq|S  
int nThreadID; //Thread's ID xJ0Q8A  
boolean bDownOver = false; //Downing is over QH) uh"  
boolean bStop = false; //Stop identical /4Df 'd  
FileAccessI fileAccessI = null; //File Access interface 5O7 x4bY  
PkqOBU*|=  
\G+uK:PC,  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +nLsiC{&  
{ 31FQ=(K  
this.sURL = sURL; .q!U@}k.  
this.nStartPos = nStart; AV t(e6H  
this.nEndPos = nEnd; C>A*L4c]F  
nThreadID = id; CH`_4UAX%  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 xs'vd:l.Pp  
} h 8ND=(  
~9tPT 0^+  
P S$6`6G  
public void run() p!XB\%sv'"  
{ dxz.%a@PW  
while(nStartPos < nEndPos && !bStop) xlhc`wdm  
{ T#>1$0yv  
7GyJmzEE  
)|d]0/<  
try{ c~bTK" u  
URL url = new URL(sURL); =}8:zO 2'{  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GfG!CG^ %  
httpConnection.setRequestProperty("User-Agent","NetFox"); z }t{bm  
String sProperty = "bytes="+nStartPos+"-"; F74^HQ*J  
httpConnection.setRequestProperty("RANGE",sProperty); 6)@Y41H]C  
Utility.log(sProperty); 4a]$4LQV  
~EV7E F  
0/vmj,&B(  
InputStream input = httpConnection.getInputStream(); 7,pn0,HI  
//logResponseHead(httpConnection); 0_A|K>7  
oD@~wcMIT0  
M6X`]R'  
byte[] b = new byte[1024]; vz~QR i*  
int nRead; 1TuN   
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @Yl&Jg2l'  
{ :X66[V&eH  
nStartPos += fileAccessI.write(b,0,nRead); u4W2 {  
//if(nThreadID == 1) "1#piJ  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~boTh  
} aYmC LLj  
Ki8]+W37  
`Dn"<-9:  
Utility.log("Thread " + nThreadID + " is over!"); O%Mi`\W@  
bDownOver = true; (|*CVI;  
//nPos = fileAccessI.write (b,0,nRead); 7I_1Lnnf  
} q@"0(Oj  
catch(Exception e){e.printStackTrace ();} Bq20U:f  
} A-8[8J  
} `Tt;)D  
)J['0DUrZK  
rEM#J"wF  
//打印回应的头信息 $;1TP|  
public void logResponseHead(HttpURLConnection con) WZ3GI l  
{ NJe^5>4`  
for(int i=1;;i++) G(;C~kHX  
{ 6oQSXB@  
String header=con.getHeaderFieldKey(i); -=+@/@nV  
if(header!=null) {p70( ]v  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G!^}z (Mgi  
Utility.log(header+" : "+con.getHeaderField(header)); w7;,+Jq  
else .o&Vu,/H  
break; v&8%t 7|  
} -9f> rH\3  
} pc=f,  
;;3oWsil}  
[ITtg?]F  
public void splitterStop() Ag6^>xb^  
{ 8,l~e8&  
bStop = true; $z"1&y)  
} gXQ s)Eyv  
??7c9l5,  
8vuA`T!~G  
} j~ 'a %P  
qkg`4'rLg  
BbV@ziL  
/* fBi6% #  
**FileAccess.java X<j(AAHE  
*//文件访问(定位,写) $U]KIHb  
package NetFox; P>i!f!o*I  
import java.io.*; %#zqZ|q  
UP})j.z  
:d!qZFln  
public class FileAccessI implements Serializable{ uE}A-\G  
{tN?)~ZQ  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 WqHsf1? N  
RandomAccessFile oSavedFile; %+{[%?xh  
long nPos; 5g$]ou  
k^Gf2%k  
RTJ\|#w  
public FileAccessI() throws IOException t.ci!#/d  
{ !qQ B}sAf  
this("",0); &.ilku/  
} V=?qU&r<+  
k v>rv37u  
!I8m(axW  
public FileAccessI(String sName,long nPos) throws IOException ZSUbPz  
{ Kz>Bw;R(  
oSavedFile = new RandomAccessFile(sName,"rw"); EV$$wrohQ`  
this.nPos = nPos; jnu!a.H  
oSavedFile.seek(nPos); X>$s>})Y  
} $1F$3"k  
G 5T{*  
!L=RhMI  
public synchronized int write(byte[] b,int nStart,int nLen) +'@j~\>^yJ  
{ nc.(bb),  
int n = -1; qpCNvhi  
try{ ]m(C}}  
oSavedFile.write(b,nStart,nLen); CHojF+e  
n = nLen; I_k!'zR[N  
} cu~\&3 R  
catch(IOException e) .EXe3!J)!  
{ :|V`QM  
e.printStackTrace (); T[<deQ  
} PE\.JU  
,ezC}V0M  
RM(MCle}  
return n; j mH=W)  
} ~@Wg3'&  
.C=I~Z  
eBs4:R_i  
} BS@x&DB  
vK10p)ZV  
9bxBm  
/* e-`=?tct  
**SiteInfoBean.java m,"N 4a@  
*/ tS@J)p+_(  
package NetFox; yG ,oSp|  
b;O@|HK&~  
x&N!SU6  
public class SiteInfoBean { l5*sCp*Z  
6HK dBW$/  
=rB=! ;  
private String sSiteURL; //Site's URL R'Uw17I  
private String sFilePath; //Saved File's Path eM1=r:jgE  
private String sFileName; //Saved File's Name &{5v[:$  
private int nSplitter; //Count of Splited Downloading File N"M?kk,  
O.HaEg/-  
6bacU#0o  
public SiteInfoBean() 6iZ:0y0t+6  
{//nSplitter的缺省值为5 ,e{|[k  
//default value of nSplitter is 5 ))<1"7D^^  
this("","","",5); Q6e;hl  
} O5lP92],  
*Bj7\8cKC  
nB+UxU@  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p#  4@  
{ '/[9Xwh9  
sSiteURL= sURL; Shm$>\~=  
sFilePath = sPath; "+@>!U  
sFileName = sName; iYE7BUH=  
this.nSplitter = nSpiltter;  uK_R#^  
,Q2?Z :l  
OZ9ud ]@\  
} r@.3.Q  
9cO m$  
~ZN]2}  
public String getSSiteURL() pp!>:%  
{ n1mqe*Mvs/  
return sSiteURL; ZnVx 'Y  
} 3ZhB 8 P  
YM(` E9{h  
]\8{z"  
public void setSSiteURL(String value) yOQEF\  
{ Y2B ",v"  
sSiteURL = value; |*5QFp  
} 1I1Z),  
|K jy4.2  
M10u?  
public String getSFilePath() / >As9|%  
{ cfg_xrW0^  
return sFilePath; -$8M#n,  
} j. m(Z}  
x|6# /m  
dl%KD8  
public void setSFilePath(String value) #G/ _FRo`  
{ Z\)emps  
sFilePath = value; OG C|elSM  
} [8b,}i 1  
u40k9vh  
'g$a.75/-  
public String getSFileName() x9Qa.Jmj  
{ 7LB#\2  
return sFileName; eL7rX"!  
} sHr!GF  
* YhX6J1  
8r 4 L4  
public void setSFileName(String value) qZ8 V/  
{ yzml4/X  
sFileName = value; o (OC3  
} | gou#zi  
7T)J{:+0!|  
pKM5<1J  
public int getNSplitter() .-0;:>  
{ wU|Y`wJmF  
return nSplitter; " * Qwaq_  
} v8< MAq  
ZV=)`E`I|  
QCI-YJ&o  
public void setNSplitter(int nCount) qZ:--,9+  
{ p(5'|eqBV  
nSplitter = nCount; Hsoe?kUHF  
} o#IQz_  
} E7*z.3  
2yFXX9!@  
4/rd r80  
/* n<x NE %  
**Utility.java &>!WhC16  
*/ tVf1]3(_>  
package NetFox; LAoX'^6  
gXR1nnK  
%mda=%Yn  
public class Utility { x7s75  
$jDp ^ -  
 ?2g\y@  
public Utility() !7:~"kk  
{ 3j2% '$>E^  
jx=2^A/i2-  
^ H,oI*  
} 9 J$z/j;X  
fYU-pdWPT  
//线程睡眠 #\&jM -.-  
public static void sleep(int nSecond) KL4Z||n  
{ D/jS4'$vA  
try{ @'K+   
Thread.sleep(nSecond); e:BKdZGW  
} CPI7&jqu  
catch(Exception e) hE-u9i  
{ N o}Ly{  
e.printStackTrace (); 8#Q=CTjF  
} iCouGd}  
} =;1MpD  
^[d|^fRH Q  
//日志 e/?>6'6 5  
public static void log(String sMsg) YdI|xu>0A^  
{ xl(];&A3  
System.err.println(sMsg); Z'%k`F  
} X3KP N  
*lN>RWbM%  
&k5 Z|d|  
public static void log(int sMsg) T/V 5pYl  
{ Q6cF <L`bW  
System.err.println(sMsg); Um k9  
} K4vl#*qn  
} O;qerE?i`  
X9f!F2x  
`]^JOw5o  
/* N'fE^jqU  
**TestMethod.java Os?`!1-  
*/ r lalr+Rf  
package NetFox; HNA/LJl[VU  
,qgph^C  
i0($@6Lh  
public class TestMethod { N1RZ  
,H3~mq]  
"%aJ 'l2  
public TestMethod() Xi'y-cV ^  
{ ///xx/weblogic60b2_win.exe +h6c Aqm]  
try{ )g9&fGYf  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R4<}kA,.  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Tn+6:<OFdO  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9L}=xX`>?  
fileFetch.start(); ta*B#2D>  
} ,X&lVv#  
catch(Exception e){e.printStackTrace ();} w. gI0`  
P9/5M4]tt  
/q4<ZS#  
} z?HP%g'M~  
).TQYrs  
~+{OSx<S  
public static void main(String[] args) 7m6@]S6  
{ We#u-#k_O  
new TestMethod(); n>tYeN)F<  
} sXm/+I^  
} [YY[E 7  
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:
10+5=?,请输入中文答案:十五