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
  • 12154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
/* )u7*YlU\I  
**SiteFileFetch.java M.K-)r,  
*/ 73/kyu-0%  
package NetFox; Q)\7(n  
import java.io.*; EG5'kYw2  
import java.net.*; EAQg4N:D7L  
7%Zl^c>q  
4!Ez#\  
public class SiteFileFetch extends Thread { `d#l o  
F]~rA! g1  
ScrEtN  
SiteInfoBean siteInfoBean = null; //文件信息Bean 6JWCB9$4  
long[] nStartPos; //开始位置 k%\_UYa  
long[] nEndPos; //结束位置 <{7CS=)  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 sDnHd9v<?t  
long nFileLength; //文件长度 v}hmI']yf  
boolean bFirst = true; //是否第一次取文件 Dm/# \y3  
boolean bStop = false; //停止标志 PMk3b3)Z  
File tmpFile; //文件下载的临时信息 hd~X c  
DataOutputStream output; //输出到文件的输出流 v\*43RL  
CW k#Amt.  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) .3Nd[+[  
public SiteFileFetch(SiteInfoBean bean) throws IOException -UaUFJa8K&  
{ q/xMM `{  
siteInfoBean = bean; &H!3]  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); [B9'/:  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); "}UJ~ j).  
if(tmpFile.exists ()) ~YHy '.  
{ Evkb`dU3n  
bFirst = false; 0uzm@'^  
read_nPos(); (#* 7LdZ  
} W=M`Bkw{  
else <}b`2/wP  
{ %sb)U~gP  
nStartPos = new long[bean.getNSplitter()]; &eV& +j  
nEndPos = new long[bean.getNSplitter()]; HlqvXt\  
} Ktg{-Xl  
((A]FOIbO  
8YC\Bw  
WO W4c&  
} 3jPua)=p  
5T;M,w6DV  
;cl\$TDL  
public void run() Z~{0XG\Y  
{ D<$~bUkxR  
//获得文件长度 <A&mc,kj  
//分割文件 FblwQ-D  
//实例FileSplitterFetch /_E8'qlx  
//启动FileSplitterFetch线程 8DbXv~3@  
//等待子线程返回 tS,nO:+x  
try{ |du@iA]dP  
if(bFirst) e2Sm.H '  
{ LtKiJ.j?A  
nFileLength = getFileSize(); eRQ}`DjTk  
if(nFileLength == -1) FX7=81**4  
{ z]ZhvH7-  
System.err.println("File Length is not known!"); a&~_ba+  
} /W'GX n  
else if(nFileLength == -2) U'zW; Lt  
{ hK"hMyH^  
System.err.println("File is not access!"); 1g6AzUXg  
} 9;s:Bo  
else 98h,VuKVaB  
{ />;1 }  
for(int i=0;i<nStartPos.length;i++) T1hr5V<U  
{ ~U`oew  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); WyVFh AuU  
} zu&5[XL  
for(int i=0;i<nEndPos.length-1;i++) (Da/$S.  
{ $8o(_8Q)  
nEndPos = nStartPos[i+1]; L+Yn}"gIs  
} ]kq{9b';  
nEndPos[nEndPos.length-1] = nFileLength; Qj~m;F!  
} d_=@1 JM>  
} 8RWfv}:X  
%)T>Wn%b]v  
')t :!#  
//启动子线程 +[*VU2f t  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %o9@[o .]  
for(int i=0;i<nStartPos.length;i++) `E>HpRcxD  
{ aO('X3?  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w\k|^  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C J S  
nStartPos,nEndPos,i); _x 'R8/  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pkpD1c^  
fileSplitterFetch.start(); <m9hM?^q  
} SV16]Vc  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =8$//$  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Kdk0#+xtP  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1eQ9(hzF  
nEndPos = " + nFileLength); ~C=I{qzF+  
// fileSplitterFetch[nPos.length-1].start(); TSqfl/UI  
D_ xPa  
lxy_O0n  
//等待子线程结束 |t*(]U2O0  
//int count = 0; ;NH 5 L,  
//是否结束while循环 9Y!N\-x`  
boolean breakWhile = false; B1T:c4:N  
:@)UI,  
SA&0f&07i  
while(!bStop) =3OK 3|  
{ QU^*(HGip  
write_nPos(); r#iZ FL3q  
Utility.sleep(500); mZ 39 s  
breakWhile = true; dt(~)*~R  
ia 1Sf3  
!!Z#'Wq  
for(int i=0;i<nStartPos.length;i++) 4s nL((  
{ zb.^ _A  
if(!fileSplitterFetch.bDownOver) ;EbGW&T  
{ !s pp*Q)#\  
breakWhile = false; Ig75bZz   
break; ^%|,G:r  
} M*FUtu  
} P:h;"  
if(breakWhile) tFt56/4  
break; 5vs~8|aRo  
nf& P Dv1  
Bz<T{f  
//count++; C,7d  
//if(count>4) bh|M]*Pq  
// siteStop(); s.I%[kada  
} eznt "Rr2  
Hs/ aU_  
\"Z^{Y[,;  
System.err.println("文件下载结束!"); AE`X4q  
} *,<A[XP  
catch(Exception e){e.printStackTrace ();} vdw5T&Q{{C  
} I|69|^  
K}"xZy Tm1  
x8k7y:  
//获得文件长度 Qd;P?W6  
public long getFileSize() HE58A.Q&  
{ D ]Q,~Y&'  
int nFileLength = -1; a0I+|fR  
try{ 52?zBl`|  
URL url = new URL(siteInfoBean.getSSiteURL()); 1=(jpy  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -V0_%Smc  
httpConnection.setRequestProperty("User-Agent","NetFox"); HA&7 ybl  
Jb~$Vrdy  
Z- |.j^n  
int responseCode=httpConnection.getResponseCode(); 0JzH dz  
if(responseCode>=400) c} )U:?6  
{ 3/c3e{,!  
processErrorCode(responseCode); K ;\~otR^  
return -2; //-2 represent access is error 2 Ya)I k{  
} lM1~ K  
YoyJnl.?u  
"1 O!Ck_n  
String sHeader; I?` }h}7.  
nZZNx  
y4*i V;"  
for(int i=1;;i++) f%vJmpg  
{ !v/5 G_pr  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2N*XzVplN  
//Utility.log(in.readLine()); Q#"p6ZmI  
sHeader=httpConnection.getHeaderFieldKey(i); Z(DCR/U=(>  
if(sHeader!=null) d: D`rpcC  
{ o V"d%ks  
if(sHeader.equals("Content-Length")) &*2\1;1tB  
{ sd4eJ  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); fkf69,+"]  
break; V]I@&*O~ r  
} Gl8D GELl;  
} R_9&V!fl  
else \kSoDY`l&  
break; Zoe>Ow8mE`  
} y/=:F=H@w  
} :})(@.H  
catch(IOException e){e.printStackTrace ();} Z] ?Tx2|7  
catch(Exception e){e.printStackTrace ();} N(i%Oxp1  
q#LB 2M  
DUH\/<^g  
Utility.log(nFileLength); ZK:dhwer  
wM.z/r\p  
(NfP2E|B  
return nFileLength; tUX4#{)q(j  
} F6>K FU8  
.*XELP=BT  
EUBJnf:q  
//保存下载信息(文件指针位置) +;z^qn  
private void write_nPos() W P7RX|7  
{ ;R[  xo!  
try{ & Tz@lvOv%  
output = new DataOutputStream(new FileOutputStream(tmpFile)); vBy t_X  
output.writeInt(nStartPos.length); 8Aq [@i  
for(int i=0;i<nStartPos.length;i++) t^ _0w[  
{ FY;\1bt<<  
// output.writeLong(nPos); MTBHFjXO  
output.writeLong(fileSplitterFetch.nStartPos); ,TeJx+z^  
output.writeLong(fileSplitterFetch.nEndPos); )Ve-)rZ  
} V~#e%&73FH  
output.close(); 3On IAk3  
} <Jt H/oN  
catch(IOException e){e.printStackTrace ();} OAigq6[,  
catch(Exception e){e.printStackTrace ();} Zop3[-  
} Mdk(FG(  
bVfFhfh*  
yx5F]Z<M2  
//读取保存的下载信息(文件指针位置) 1.S7MSpTV  
private void read_nPos() W,sU5sjA  
{ 8yW8F26  
try{ wyzx9`5~d  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /<[S> ;!kr  
int nCount = input.readInt(); &6]+a4  
nStartPos = new long[nCount]; '?| (QU:)F  
nEndPos = new long[nCount]; feJzX*u  
for(int i=0;i<nStartPos.length;i++) 9Z?P/ o  
{ M:t!g %  
nStartPos = input.readLong(); /#mq*kNIM6  
nEndPos = input.readLong(); .II*wK k  
} { 'A`ram  
input.close(); H~Z$pk%  
} qY,z,o AF  
catch(IOException e){e.printStackTrace ();} v[$-)vs*ag  
catch(Exception e){e.printStackTrace ();} C]@v60I  
} :r4]8X-  
}"} z7Xb0  
So?.V4aD_  
private void processErrorCode(int nErrorCode) 3=[#(p:  
{ W&M=%  
System.err.println("Error Code : " + nErrorCode); |gXtP-  
} N$'/J-^  
2!-?  
oJ\)-qSf  
//停止文件下载 (CUrFZT$  
public void siteStop() 1Yr&E_5/  
{ N5W;Zx]  
bStop = true; yH`4 sd  
for(int i=0;i<nStartPos.length;i++) !-G'8a|7  
fileSplitterFetch.splitterStop(); ( mV*7Z  
4Vv~  
u_kcuN\Sq  
} ceiUpWMu,  
} k8>(-W"A  
//负责部分文件的抓取 }s*H| z  
**FileSplitterFetch.java VSm[80iR0  
*/ 8]SJ=c"}Xf  
package NetFox; $? 'JePC  
'*4>&V.yX  
*[ ' n8Z  
import java.io.*; i 4sd29v  
import java.net.*; D8 S?xK7[  
qcN{p7=0  
] lBe   
public class FileSplitterFetch extends Thread { ~* R:UTBtw  
_:R Q9x'  
gK&MdF*  
String sURL; //File URL ,(1n(FZ  
long nStartPos; //File Snippet Start Position !yUn|v>&p  
long nEndPos; //File Snippet End Position ` u|8WK:  
int nThreadID; //Thread's ID B: '}SA{  
boolean bDownOver = false; //Downing is over 6CQ.>M:R  
boolean bStop = false; //Stop identical $5(_U  
FileAccessI fileAccessI = null; //File Access interface -|1H-[Y(  
w@K4u{|  
W|~Jl7hs8Q  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;HKb  
{ 4blw9x N  
this.sURL = sURL; It5U=PU  
this.nStartPos = nStart; )^Ha?;TS  
this.nEndPos = nEnd; iTX:*$~I  
nThreadID = id; 1\'?.  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 tVAWc$3T  
} ;f]p`!] 3  
h;q= <[h\  
m=s aUhI*9  
public void run() {"^LUw8fd  
{ q+j.)e  
while(nStartPos < nEndPos && !bStop) s=[Tm}[  
{ uq/z.m  
Sio> QL Y  
,^Cl?\9"  
try{ +2DzX/3  
URL url = new URL(sURL); o+NPe36  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 73n|G/9n[  
httpConnection.setRequestProperty("User-Agent","NetFox"); 4yZ'+\ +I  
String sProperty = "bytes="+nStartPos+"-"; `&3hfiI}  
httpConnection.setRequestProperty("RANGE",sProperty); For`rfR  
Utility.log(sProperty); |E& F e8  
@Feusprs  
I "8:IF  
InputStream input = httpConnection.getInputStream(); v jTs[eq>  
//logResponseHead(httpConnection); YsX&]4vzm  
2yB@)?V/  
n;Nr[hI  
byte[] b = new byte[1024]; *qX!  
int nRead; p"xti+2,  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) o {W4@:Ib  
{ t)#d R._q  
nStartPos += fileAccessI.write(b,0,nRead); .o27uB.  
//if(nThreadID == 1) '}nH\?(  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S.: m$s  
} U@ ;W^Mt  
gY\g+df-  
r Jo8|  
Utility.log("Thread " + nThreadID + " is over!"); V`ODX>\  
bDownOver = true; cWNZ +Q8Y  
//nPos = fileAccessI.write (b,0,nRead); `6R.*hq  
} [lU0TDq  
catch(Exception e){e.printStackTrace ();} MD"a%H#p  
} N WSm  
} )aV\=a |A  
"mbjS(-eg  
}NH\Q$IU  
//打印回应的头信息 *btLd7c%  
public void logResponseHead(HttpURLConnection con) Q|gw\.]$&[  
{ X@["Jjp  
for(int i=1;;i++) Z+gG.|"k  
{ '8k{\>  
String header=con.getHeaderFieldKey(i); '7Ad:em  
if(header!=null) A^m]DSFOO  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^| b]E  
Utility.log(header+" : "+con.getHeaderField(header)); ZqDanDM  
else vb&1 S  
break; =XRTeIZ  
} &Zzd6[G+  
} +vDEDOS1  
N7wKaezE  
dy }O6  
public void splitterStop() QbN7sg~~  
{ slQxz;t  
bStop = true; cC4 2b2+  
} GlVb |O"  
/LH# 3  
n?UFFi+a  
} Gp l  
OI8Hf3d=  
=do*(  
/* HsF8$C$z  
**FileAccess.java ! R b  
*//文件访问(定位,写) ~x(1g;!^  
package NetFox; E43Gk!/|(  
import java.io.*; Wl29xY}`{!  
We8n20wf<  
L~Hl?bK  
public class FileAccessI implements Serializable{ h/LlH9S:!  
^(Y}j8sj  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \68x]q[  
RandomAccessFile oSavedFile; Dc1tND$X3g  
long nPos; 2 cB){.E  
<n+]\a97*  
x5X;^.1Fr  
public FileAccessI() throws IOException >qqI6@h]c  
{ Juhi#&`T  
this("",0); #1-2)ZO.  
} _EusY3q  
7])cu>/  
o94]:$=~  
public FileAccessI(String sName,long nPos) throws IOException 9 rMP"td  
{ <[oPh(!V  
oSavedFile = new RandomAccessFile(sName,"rw"); 5z T~/6-(  
this.nPos = nPos; ]Qu.-F#g  
oSavedFile.seek(nPos); 3iKy>  
} \ZOH3`vq  
l DWg%pI+  
+WH|nV~lQ  
public synchronized int write(byte[] b,int nStart,int nLen) #W]4aZ1  
{ #A:+|{H"  
int n = -1; ]N& Y25oT5  
try{ #GlQwk3  
oSavedFile.write(b,nStart,nLen); 5n1aRA1  
n = nLen; ZCcKY6b  
} sOf;I]E|  
catch(IOException e) 1DTA Dh0  
{ t_+Xt$Q7C  
e.printStackTrace (); ='\Di '*  
} ./KXElvQ%  
e7$ZA#A_5v  
6m\MYay  
return n; QAk.~ ob  
} wnPg).  
liuw!  
yu~o9  
} AeZ__X  
/uNgftj  
y8!#G-d5  
/* lQq&tz,  
**SiteInfoBean.java Eq\PSa=gz  
*/ fqY; > Z  
package NetFox; `w;8xD(  
fPA5]a9  
2VZdtz  
public class SiteInfoBean { JO&~mio  
xh90qm  
>QcIrq%=  
private String sSiteURL; //Site's URL Vzmw%f)_+  
private String sFilePath; //Saved File's Path 7<Yf  
private String sFileName; //Saved File's Name L3@upb  
private int nSplitter; //Count of Splited Downloading File Ld9YbL:  
$*k9e^{S  
2C &G' @>  
public SiteInfoBean() AWG;G+  
{//nSplitter的缺省值为5 O'i!}$=g  
//default value of nSplitter is 5 -,Oq=w*EV  
this("","","",5); w y\0o  
} J?1U'/Wx2  
"J_#6q*  
p!_3j^"{  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [2l2w[7Rid  
{ <aPbKDF~V  
sSiteURL= sURL; nRSiW*;R  
sFilePath = sPath; kLfk2A;'i  
sFileName = sName; Y+kfMAv  
this.nSplitter = nSpiltter; kgl7l?|O  
&| guPZ  
6 o!*bWh  
} '  ~F  
q\r@x-&g+  
;dR4a@  
public String getSSiteURL() xis],.N  
{ })#SjFq<V  
return sSiteURL; iL6Yk @  
} ,P.yl~'Al  
$-Yq?:  
q-lejVS(g  
public void setSSiteURL(String value) ?r}'0dW  
{ YR? ujN  
sSiteURL = value; V:Lq>rs#  
} 8=T[Y`;x  
#sRkKl|  
|RS(QU<QE  
public String getSFilePath() \Aa{]t  
{ OBm#E}  
return sFilePath; brpsZU  
} ToXgl4:kd  
!VoAN5#;  
R2` -*PZ_  
public void setSFilePath(String value) (]}52%~  
{ >69-[#P!  
sFilePath = value; 6 *GR_sMm  
} Ks>l=5~v|  
S5(VdMd"^  
6oA2"!u^w  
public String getSFileName() I%Yeq"5RB  
{ WW&ag r  
return sFileName; +k<0: Fi  
} ^fq^s T.$  
v{44`tR   
[/+}E X  
public void setSFileName(String value) = 9K5f# ;e  
{ ` v"p""_H  
sFileName = value; 5IJm_oy  
} p\).zuEf.  
`m_ ('N  
z=[?&X]O9b  
public int getNSplitter() 1<(('H  
{ gT&s &0_7  
return nSplitter; ~ _G W  
} |~d8j'rt  
TaqqEL  
DKnlbl1^?  
public void setNSplitter(int nCount) _t7}ny[  
{ 5%#V>|@e#  
nSplitter = nCount;  nPRv.h  
} xJ(}?0h-X  
} n8RE  
a@ v}j&  
O>tz;RU  
/* ,"xr^@W  
**Utility.java )xxpO$  
*/ \ y}!yrQ  
package NetFox; _+*+,Vx  
vP. ^j7wB  
\&jmSa=]l  
public class Utility { 7ZR0cJw;  
VsjE*AJpe  
TR J5m?x  
public Utility() "IuHSjP  
{ vjz 'y[D  
AL{r/h  
hVe39BBtO  
} g=)OcTd#  
ZT d)4f  
//线程睡眠 b uOpHQn  
public static void sleep(int nSecond) *Ud=x^JxO  
{ Ucqn 3&  
try{ dVKctt'C  
Thread.sleep(nSecond); t E(_Cg  
} sgfci{~  
catch(Exception e) 9h/JW_  
{ }|9!|Q  
e.printStackTrace (); ?qJt4Om  
} LLD#)Jl{?  
} 7) zF8V  
xN +Oca  
//日志 3 [r9v!l  
public static void log(String sMsg) Ej#pM.  
{ |?\J,h  
System.err.println(sMsg); *m6h(8(7Z  
} rUxjm\  
3k_bhK zI  
s,|"s|P  
public static void log(int sMsg) Tg yY 9  
{ KSgYf;  
System.err.println(sMsg); (`)ZR %i  
} S-2@:E  
} vhE^jS<Tg  
M$$Lsb [  
(CR]96n  
/* CwdeW.A"j  
**TestMethod.java h#~\-j9>  
*/ Qk[YF  
package NetFox; 08MY=PC~R  
(,XbxDfM  
VBq|j"o0"  
public class TestMethod { N_liKhq  
k esuM3  
C;\R 62'  
public TestMethod() 6 6C_XT  
{ ///xx/weblogic60b2_win.exe 1a]QNl_x  
try{ UNF@%O4_T  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); DcRvZH  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); E5QQI9ea  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ZGsI\3S  
fileFetch.start(); y"T(Unvc  
} KJYcP72P  
catch(Exception e){e.printStackTrace ();} H aA2y  
t$EL3U/(  
+aZcA#%  
} (b#4Z  
?8!\VNC.  
3k# h!Z  
public static void main(String[] args) G/N1[)  
{ E2i'lO\P  
new TestMethod(); :>K8oE  
} Y_= ]w1  
} *b,4qMr  
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 或 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