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
  • 10472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
/* GWhAjL/N  
**SiteFileFetch.java <m,yFk  
*/ tRnW%F5  
package NetFox; {Y91vXTz7  
import java.io.*; 6@q[tN7_^  
import java.net.*; oL'1Gm@X?  
.3<IOtD=  
Jh4&Qh|t  
public class SiteFileFetch extends Thread { x$GsDV  
xDJ+BQ<1A  
l(#ke  
SiteInfoBean siteInfoBean = null; //文件信息Bean tIb21c q  
long[] nStartPos; //开始位置 ny(GTKoUz  
long[] nEndPos; //结束位置 eQFb$C]R}y  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 7TkxvSL X  
long nFileLength; //文件长度 ^mueFw}\  
boolean bFirst = true; //是否第一次取文件 ;Q=GJ5`B  
boolean bStop = false; //停止标志 {M r~%y4  
File tmpFile; //文件下载的临时信息 ^2^|AXNES  
DataOutputStream output; //输出到文件的输出流 5!F\h'E  
s S5fd)x  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) yd ND$@; Z  
public SiteFileFetch(SiteInfoBean bean) throws IOException HNy/ -  
{ x8?x/xE  
siteInfoBean = bean; 5 n+ e  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); {kPe#n>xT  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); q{cp|#m#G  
if(tmpFile.exists ()) 3z)"U  
{ r1oku0o  
bFirst = false; $54=gRo^  
read_nPos(); <D!c ~*[  
} /3Nb  
else H5rPq_R  
{ P:(EU s}0  
nStartPos = new long[bean.getNSplitter()]; n2d8;B#  
nEndPos = new long[bean.getNSplitter()]; N3gNOq&  
} 0UGiPH,()  
d"I28PIS"  
TcD[Teu  
FU\/JF.j  
} )!k_Gb`#X  
~#"7,rQp  
)ojx_3j8  
public void run() N xb\[  
{ h zZ-$IX X  
//获得文件长度 cc41b*ci$  
//分割文件 R6q4 ["  
//实例FileSplitterFetch iog # ,  
//启动FileSplitterFetch线程 8jggc#.  
//等待子线程返回 e(~'pk"mZ  
try{ :YqQlr\  
if(bFirst) LiZdRr  
{ kxm:g)`=[  
nFileLength = getFileSize(); 1GG>.RCP  
if(nFileLength == -1) lC=N:=Mu  
{ }2ql?K  
System.err.println("File Length is not known!"); m\/,cc@,  
} > X[|c"l.  
else if(nFileLength == -2) p9AZ9xr  
{ ]D LZ&5pv  
System.err.println("File is not access!"); OG`|td  
} %9T~8L @.  
else SbS$(Gt#Bv  
{ j9URl$T:  
for(int i=0;i<nStartPos.length;i++) 5=Kq@[(4  
{ C}mYt/  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); eC6>yD6D  
} \ fK47oV  
for(int i=0;i<nEndPos.length-1;i++) |P~O15V*Q  
{ K`Bq(z?/  
nEndPos = nStartPos[i+1]; nTys4 R  
} 3s`V)aXP  
nEndPos[nEndPos.length-1] = nFileLength; =Kc|C~g  
} EqD^/(,L2  
} j?:`-\w5  
4llD6&%  
J?UA:u  
//启动子线程 W/ g|{t[  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e9CP802#2  
for(int i=0;i<nStartPos.length;i++) ^W Y8-6  
{ 0 kf(g156  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +"cRhVR  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), + a-wv  
nStartPos,nEndPos,i); #K=b%;>  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N;-/wip  
fileSplitterFetch.start(); 59{;VY81  
} >u=%Lz"J  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -7>^ rR V  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `"a? a5]k  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8P,l>HA  
nEndPos = " + nFileLength); WD15pq l  
// fileSplitterFetch[nPos.length-1].start(); K;oV"KRK  
o]Z _@VI  
gtD   
//等待子线程结束 t< sp%zXZ  
//int count = 0; w&p~0cA~  
//是否结束while循环 _*s~`jn{H  
boolean breakWhile = false; NWEhAj<w  
UT3bd,,  
\un sh^M  
while(!bStop) i[$-_  
{ .#*D!;f  
write_nPos(); pw@`}cM=  
Utility.sleep(500); ]\A1mw-T  
breakWhile = true; w#*/y?"D  
_ XE;-weE  
`-VG ?J  
for(int i=0;i<nStartPos.length;i++) w6vLNX  
{ wJ6_I$>  
if(!fileSplitterFetch.bDownOver) :qxm !P  
{ RX:R*{]-  
breakWhile = false; 1p8:.1)q  
break; ;0IvF#SJ(.  
} `9/0J-7*  
} 'KH lrmnr  
if(breakWhile) .iFViVZC  
break; '%R<"  
~gP7s_ qr{  
qQ^d9EK'?~  
//count++; tcZa~3.  
//if(count>4) & =G)NeT_  
// siteStop(); Te# ]Cn|  
} PPEq6}  
$=/rGpAk  
Qh*)pt]n  
System.err.println("文件下载结束!"); G'u|Q mb1  
} 'e F%  
catch(Exception e){e.printStackTrace ();} `M&P[ .9Pz  
} !X-9Ms}(d  
j(j#0dXLh  
\.o=icOx  
//获得文件长度 # Mu<8`T-  
public long getFileSize() ^w.]Hd 2  
{ 4Rx~s7l  
int nFileLength = -1; 6Lb{r4^  
try{ <PX.l%  
URL url = new URL(siteInfoBean.getSSiteURL()); z<!O!wX_aI  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >Iuzk1'S  
httpConnection.setRequestProperty("User-Agent","NetFox"); G~"z_ (  
u$C\E<G^  
h\(B#SN  
int responseCode=httpConnection.getResponseCode(); :$NsR*Cq*9  
if(responseCode>=400) GQb i$kl  
{ eH %Ja[  
processErrorCode(responseCode); I!P4(3skAB  
return -2; //-2 represent access is error 8) HBh7/  
} c&E]E(  
2`EVdl7B]  
1B 5:s,Oyj  
String sHeader; A_Rrcsl4  
tAERbiH  
Lbcy:E*g  
for(int i=1;;i++) k@yh+v5  
{ ,]ga[  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S<"oUdkz  
//Utility.log(in.readLine()); {Ur7# h5  
sHeader=httpConnection.getHeaderFieldKey(i); gljo;f:  
if(sHeader!=null) w8p8 ;@  
{ GF*>~_Yr  
if(sHeader.equals("Content-Length")) :5J_5,?;`  
{ p}uncIod  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); pr_>b`p6  
break; 9YD\~v;x  
} eeM?]J-  
} 8] `Ru5nd  
else \Wr,<Y  
break; }9^@5!qX  
} {{\ce;hN  
} cMaOM}mS  
catch(IOException e){e.printStackTrace ();} 7\Co`J>p2  
catch(Exception e){e.printStackTrace ();} ,[* ;UR  
*$S#o#5  
,!Q]q^{C:W  
Utility.log(nFileLength); QOH<]~3J  
Ke!'gohv  
X3',vey  
return nFileLength; dxK9:IX  
} (,B#t7ka  
Ird|C[la  
2s\BY%XY  
//保存下载信息(文件指针位置) /,2rjJ#b  
private void write_nPos() ;'0=T0\  
{ D/CIA8h3  
try{ .fp&MgiQ  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5pfYEofK[  
output.writeInt(nStartPos.length); H>XFz(LWh  
for(int i=0;i<nStartPos.length;i++) XRxj  W  
{ `:p1&OS  
// output.writeLong(nPos); KnGTcoXg_  
output.writeLong(fileSplitterFetch.nStartPos); tlQC6Fb#  
output.writeLong(fileSplitterFetch.nEndPos); >&Y-u%}U  
} U<^F4*G  
output.close(); U\zD,<I9  
} o:~LF6A-  
catch(IOException e){e.printStackTrace ();} bWmw3w  
catch(Exception e){e.printStackTrace ();} eM2|c3/  
} 'RbQj}@x  
* ?]~ #  
=^tA_AxVw  
//读取保存的下载信息(文件指针位置) iX"C/L|JN  
private void read_nPos()  U>a\j2I  
{ Jxa4hM0  
try{ Yf}xwpuLk  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g9~]s 9  
int nCount = input.readInt(); pDl3!m  
nStartPos = new long[nCount]; D=+NxR[  
nEndPos = new long[nCount]; IeP WOpj3  
for(int i=0;i<nStartPos.length;i++) TB!(('  
{ *2e!M^K<  
nStartPos = input.readLong(); QI_4*  
nEndPos = input.readLong(); sOpep  
} l63hLz  
input.close(); BUsV|e\  
} _las;S'oa  
catch(IOException e){e.printStackTrace ();} H43MoC  
catch(Exception e){e.printStackTrace ();} }Wh6zT)  
} ,R2U`EO;  
LT VF8-v  
b~w=v_[(I  
private void processErrorCode(int nErrorCode) mbxbEqz  
{ }D;WN@],  
System.err.println("Error Code : " + nErrorCode); 2oCkG~j  
} _zMgoc7  
=Vw 5q},3  
U*)m' ,  
//停止文件下载 oD.r `]k  
public void siteStop() _S`o1^Ad  
{ CU)|-*uiK  
bStop = true; -7{ $ Vj  
for(int i=0;i<nStartPos.length;i++) 'hqBo|  
fileSplitterFetch.splitterStop(); &JP-O60  
5Qh?>n>*  
!mMpb/&&S  
} bB}5U@G|  
} X3%Ic`Lq#  
//负责部分文件的抓取 Ul+Mo&y-  
**FileSplitterFetch.java T'H::^9:E  
*/ n, i'Dhzk  
package NetFox; N?P%-/7  
oCS2E =O&  
nNt1C  
import java.io.*; Zd:Taieh@  
import java.net.*; ep/Y^&$M  
04U")-\O  
Y>+y(ck  
public class FileSplitterFetch extends Thread { N!2Rl  
nh>K`+>co  
cV{o?3<:B  
String sURL; //File URL F4L;BjnJ  
long nStartPos; //File Snippet Start Position \Ae9\Jp8M  
long nEndPos; //File Snippet End Position x1&W^~  
int nThreadID; //Thread's ID 6CbxuzYer  
boolean bDownOver = false; //Downing is over $~;D9  
boolean bStop = false; //Stop identical -E"GX  
FileAccessI fileAccessI = null; //File Access interface /X'(3'a  
G 2!xPHz  
\QE)m<GUe  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^= 0m-/  
{ ]X Z-o>+ ,  
this.sURL = sURL; `;l.MZL!  
this.nStartPos = nStart; .iX# A<E}  
this.nEndPos = nEnd; *+)AqKP\Kv  
nThreadID = id; ={>Lrig:l  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \*f;Xaa  
} e [_m< e  
 Q6'x\  
rgmF:C  
public void run() c(;a=n(E#  
{ DwHF[]v'  
while(nStartPos < nEndPos && !bStop) YuZ"s55zU{  
{ N- H^lqD  
l 'DsZ9y@2  
3"n\8#X{  
try{ ,L bBpi=TJ  
URL url = new URL(sURL); +l3=3  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0sca4G0{  
httpConnection.setRequestProperty("User-Agent","NetFox"); 10!wqyj&  
String sProperty = "bytes="+nStartPos+"-"; ,<BbpIQ2o  
httpConnection.setRequestProperty("RANGE",sProperty); *}k;L74|  
Utility.log(sProperty); ^sN (  
yeDsJ/L  
^V$Ajt  
InputStream input = httpConnection.getInputStream(); ivDGZI9  
//logResponseHead(httpConnection); M])dJ9&e  
FIxFnh3~  
]I3!fEAWR  
byte[] b = new byte[1024]; JR CrZW}  
int nRead; <S?ddp2  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) < -W*$?^  
{ MUfG?r\t  
nStartPos += fileAccessI.write(b,0,nRead); +)o}c"P!  
//if(nThreadID == 1) `\Hf]b  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A+hT3;lp  
} (jU6GJRP  
H"ZZ.^"5FV  
;22oY>w  
Utility.log("Thread " + nThreadID + " is over!"); m3Il3ZY.  
bDownOver = true; @2'Mt}R>  
//nPos = fileAccessI.write (b,0,nRead); 2{|h8oz  
} L_=3<n E  
catch(Exception e){e.printStackTrace ();} T^J>ZDA  
} 0d8%T<=J  
} GFr|E8  
u#}[ZoI  
x#Sqn#  
//打印回应的头信息 F 8B#}%JE  
public void logResponseHead(HttpURLConnection con) ( Jz;W<E  
{ pPd#N'\*  
for(int i=1;;i++) i[wb0yL  
{ yR(x+ Gs{]  
String header=con.getHeaderFieldKey(i); a!O0,y  
if(header!=null) Q0EiEX)  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~ vqa7~}m  
Utility.log(header+" : "+con.getHeaderField(header)); )iFJz/n>  
else /cU<hApK  
break; W`c'=c  
} HRB<Y mP@  
} yX~v-N!X  
s%<eD  
[l,Ei?  
public void splitterStop() 3}e%[AKh  
{ ^o7;c[E`  
bStop = true; M)SEn/T-  
} 8#vc(04(  
:9k Ty:  
fW?o@vlO  
} N<~ku<nAU  
O{ #=d  
F_CYYGZ  
/* +SwR+H)?  
**FileAccess.java JQ"U4GVp  
*//文件访问(定位,写) iX)%Q  
package NetFox; CHz+814  
import java.io.*; &RfC"lc  
ocs+d\  
TqnT S0fx  
public class FileAccessI implements Serializable{ >y,-v:Vy  
%n*-VAfE\  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 D-c`FG'  
RandomAccessFile oSavedFile; 'q`^3&E  
long nPos; cFJY^A  
1YH+d0UGn  
MG.` r{5  
public FileAccessI() throws IOException Hro-d 1J7  
{ Dd\jHF>u  
this("",0); 9Q"'" b*?z  
} >3Eo@J,?d  
I"GB <oB  
EVGt 5z  
public FileAccessI(String sName,long nPos) throws IOException +llR204  
{ :8OZ#D_Hl  
oSavedFile = new RandomAccessFile(sName,"rw"); P?k0zwOlBl  
this.nPos = nPos; >Z5gSs0  
oSavedFile.seek(nPos); :\|SQKD  
} 9E6_]8rl  
`E>1>'  
Ig f&l`\  
public synchronized int write(byte[] b,int nStart,int nLen) RN e^; B  
{ 76`8=!]R  
int n = -1; }9FSO9*&}  
try{ @<elq'2  
oSavedFile.write(b,nStart,nLen); Fx2bwut.K  
n = nLen; yPal<c  
} 3qf Ym}d  
catch(IOException e) r[*Vqcz  
{ <_-hRbS  
e.printStackTrace (); X<I+&Zi  
} /#)/;  
xsD($_  
j-lfMEa$o  
return n; %4gg@Z9  
} ;'cN<x)% |  
VcXq?f>\  
()6wvu}  
} >7QvK3S4%  
=Lf,?"S  
XzEc2)0'v  
/* )84~ugs  
**SiteInfoBean.java l`f/4vy  
*/ N$U$5;r~`  
package NetFox; md"!33 @  
c"B{/;A  
G6$kv2(k`@  
public class SiteInfoBean { 'ZDp5pCC;  
oY933i@l)P  
v]B3m  
private String sSiteURL; //Site's URL G?Q3/y(  
private String sFilePath; //Saved File's Path @}}$zv6l,  
private String sFileName; //Saved File's Name ;6>2"{NW  
private int nSplitter; //Count of Splited Downloading File ]7Tkkw$  
YTUZoW2  
H}hiT/+$  
public SiteInfoBean() `)T13Xv  
{//nSplitter的缺省值为5 -;^j:L{   
//default value of nSplitter is 5 )-a'{W/t  
this("","","",5); &E.^jR~*  
} ewctkI$,5  
+JjW_Rl?=V  
n[lJLm^(_C  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^\4h<M  
{ {y=j?lD  
sSiteURL= sURL; iKX-myCz  
sFilePath = sPath; ]&lY%"U$i  
sFileName = sName; _./Sk|C  
this.nSplitter = nSpiltter; 1;Ou7T9w  
wea-zN  
b4[bL2J$h1  
} H9YW  
Y^$X*U/q%U  
Y 0d<~*  
public String getSSiteURL() t gI{`jS%  
{ TFlet"ge=  
return sSiteURL; j+$rj  
} um!J]N^  
Rh_np  
O$_)G\\\m  
public void setSSiteURL(String value) ]>=}*=  
{ /|C*  
sSiteURL = value; -zOdU}91Ao  
} bk;?9%TW  
H[,i{dD  
f4 P8Oz  
public String getSFilePath() I|gB@|_~  
{ &$`P,i 1)  
return sFilePath; F\KjEl0  
} bDL,S?@  
|H;F7Y_  
Qz5sxi  
public void setSFilePath(String value) J^SdH&%Z  
{ a_f~N1kq  
sFilePath = value; cW@Zd5&0S  
} +ElfZ4  
hT`J1nNt  
O}-jCW;K  
public String getSFileName() zzTfYf)  
{ e2s]{obf  
return sFileName; HK,cJah q  
} }wr{W:j  
g{OwuAC_  
GpY"f c%  
public void setSFileName(String value) w$zu~/qV2  
{ 3x{ t(  
sFileName = value;  oM2l-[-  
} Wh+{mvu#  
I&}L*Z?`  
SUCM b8  
public int getNSplitter() n.!#P|  
{ ZSjMH .Ij"  
return nSplitter; yu!h<nfzA  
} Ugu[|,  
#5cEV'm;  
Cl; oi}L  
public void setNSplitter(int nCount) Rdvk ml@@  
{ DFZkh^PFd  
nSplitter = nCount; I`-8Air5f  
} 5na~@-9p  
} Uc7mOa}4  
S?1AFI9{   
` Q|*1  
/* (eI5_`'VC  
**Utility.java JjPKR?[>  
*/ PF)jdcX  
package NetFox; adCU61t  
`^u>9v-+'  
*6sl   
public class Utility { K2M~-S3  
qLn/2  
+T|JK7  
public Utility() [ey:e6,T9  
{ ZZ2vvtlyG  
`Nz/O h7  
4r>6G/b8*  
} 8ja$g,  
7X0Lq}G@  
//线程睡眠 %HGD;_bhI  
public static void sleep(int nSecond) U 9_9l7&r  
{ (D#B_`;-  
try{ Oft-w)cYz,  
Thread.sleep(nSecond); -I*^-+>H  
} H$=e -L`@  
catch(Exception e) QLXN*c  
{ Vq2y4D?  
e.printStackTrace (); HG^B#yX  
} .{ocV#{s  
} jF ^~p9z  
msP{l^%0  
//日志 rID#`:Hl-|  
public static void log(String sMsg) EN$2,qf  
{ K-bD<X  
System.err.println(sMsg); *W.C7=  
} <;vbsksZeH  
f,h J~  
h].<t&  
public static void log(int sMsg) "$#xK|t  
{ ;YA(|h<  
System.err.println(sMsg); |SoCRjuCPM  
} }YB*]<]  
} :o|\"3  
\w/yF4,3<w  
`IP/d  
/* +ln9c  
**TestMethod.java +]*zlE\N`  
*/ ozmrw\_}[  
package NetFox; UJD 0K]s  
(U&tt]|  
Li!Vx1p;u.  
public class TestMethod { )m`<H>[Eb=  
Rn}l6kbM  
gp5_Z-me  
public TestMethod() *,e:]!*  
{ ///xx/weblogic60b2_win.exe ]JCvyz H  
try{ -=%@L&y1  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KC/=TSSXd.  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -m)X]]~C  
SiteFileFetch fileFetch = new SiteFileFetch(bean); pOGeru u?  
fileFetch.start(); 5Sm}n H  
} GR&z,  
catch(Exception e){e.printStackTrace ();} .:@Ykdm4I  
fKeT,U`W  
 'C`U"I  
} _7H7 dV  
?{/4b:ua  
G/b^|;41  
public static void main(String[] args) wG~`[>y (  
{ 3vuivU.3  
new TestMethod(); "3Uv]F  
} !Fca~31R'  
} FG%X~L<d,)  
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