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
  • 8395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
/* :k(aH Ua  
**SiteFileFetch.java  p&ZD1qa  
*/ M ?F({#]  
package NetFox; T_\GvSOI  
import java.io.*; .^Ek1fi.  
import java.net.*; nnr(\r~  
Qz/=+A/4  
<Pf W  
public class SiteFileFetch extends Thread { '<XG@L  
n*_FC  
Dk[[f<H_{  
SiteInfoBean siteInfoBean = null; //文件信息Bean {},G xrQm  
long[] nStartPos; //开始位置 E-! `6  
long[] nEndPos; //结束位置 6oJ~Jdn'  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 sq :ff  
long nFileLength; //文件长度 pLk?<y  
boolean bFirst = true; //是否第一次取文件 t,=khZ  
boolean bStop = false; //停止标志 ?rr%uXQjH  
File tmpFile; //文件下载的临时信息 E@[`y:P  
DataOutputStream output; //输出到文件的输出流 :r#FI".qx  
a2p<HW;)m  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) (wbG0lu  
public SiteFileFetch(SiteInfoBean bean) throws IOException 81aY*\  
{ ^Z}INUv]7  
siteInfoBean = bean; iL5+Uf)E3  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); seq S*^7  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); *K0CUir|  
if(tmpFile.exists ()) r[~K m5  
{ %} \@Wk~  
bFirst = false; .Olq_wuH  
read_nPos(); >eJk)qM  
} >gVR5o  
else srC'!I=s>8  
{ 0! !pNK%(  
nStartPos = new long[bean.getNSplitter()]; )8e_<^M  
nEndPos = new long[bean.getNSplitter()]; .\1XR  
} NFc< %#H  
neOR/]  
[g<6i.<I  
0~^opNR  
} 8HTV"60hTs  
oYqlN6n,=6  
^#"!uCq]gM  
public void run() oOJN?97!k  
{ E#_}y}7JY  
//获得文件长度 rY($+O@a<  
//分割文件 %iF< px?Vc  
//实例FileSplitterFetch ^WM)UZEBC  
//启动FileSplitterFetch线程 % ]  
//等待子线程返回  8tPq5i  
try{ BIX%Bu0'f  
if(bFirst) )e{~x u  
{ Yo:>m*31  
nFileLength = getFileSize(); uZW1 :cx  
if(nFileLength == -1) 59ro-nA9v  
{ 7?cZ9^z`w  
System.err.println("File Length is not known!"); xt40hZ$  
} Oja)J-QXb  
else if(nFileLength == -2) mDj:w#q  
{ dr:)+R  
System.err.println("File is not access!"); V&NOp  
} |QxDjL<&t4  
else G?8,&jP~T  
{ b/ur!2yr  
for(int i=0;i<nStartPos.length;i++) Ku&0bXP  
{ OGh b Ha  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); v>0xHQD*<M  
} TX8,+s+  
for(int i=0;i<nEndPos.length-1;i++) Xt9?7J#\T  
{ %.[GR  
nEndPos = nStartPos[i+1]; KWhw@y-5j@  
} eGnc6)x@C  
nEndPos[nEndPos.length-1] = nFileLength; +mV4Ty  
} ks'25tv}F  
} R+, tn,<<  
Q{mls  
 ZY keW  
//启动子线程 PZH]9[H  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [)9bR1wh  
for(int i=0;i<nStartPos.length;i++) ?u 9) GJO[  
{ Gl}=Q7  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :S?'6lOc(  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), y]M/oH  
nStartPos,nEndPos,i); YceiP,!4?v  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZK_IK)g  
fileSplitterFetch.start(); )SUT+x(DU  
} m5f/vb4l  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A-.jv  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [4( TG<I  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", v@"xEf1n[  
nEndPos = " + nFileLength); RR^I*kRH  
// fileSplitterFetch[nPos.length-1].start(); 0B1*N_.L@  
$5cLhi"`  
}q27M  
//等待子线程结束 #). om*Xh  
//int count = 0; /3rt]h"  
//是否结束while循环 bIe>j*VPh@  
boolean breakWhile = false; Lj({ T'f(  
H6rWb6i  
?$F:S%eH  
while(!bStop) 0XL x@FYn  
{  {EZ ;  
write_nPos(); ]@M$.msg@  
Utility.sleep(500); . |KxQn}  
breakWhile = true; -twIF49  
GVn7#0x  
5GT,:0  
for(int i=0;i<nStartPos.length;i++) ZK3?"|vhC  
{ #.a4}ya19  
if(!fileSplitterFetch.bDownOver) =4+UX*&i?.  
{ kw|bEL9!u  
breakWhile = false; <hQ@]2w$  
break; \L6U}ZQ2V  
} (/Z~0hA[Q  
} @T]gw J  
if(breakWhile) QBY7ZT05Gt  
break; d*8 c,x  
B>#zrCD  
>x&$lT{OY  
//count++; `Z]a6@w~  
//if(count>4) /]<0`nI.  
// siteStop(); VLu_SXlo*  
} Ri aO`|1  
EmG`ga)s  
LQNu]2  
System.err.println("文件下载结束!"); m7^a4  
} g|e^}voRM  
catch(Exception e){e.printStackTrace ();} #qm<4]9 1  
} ks sXi6^  
u\&oiwSIP  
n4(w?,w }  
//获得文件长度 ANp4yy+  
public long getFileSize() -5kq9Dy\,  
{ sVaWg?=qs'  
int nFileLength = -1; "op1xto  
try{ kH1l -mxz  
URL url = new URL(siteInfoBean.getSSiteURL()); !bT0kP$3}  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~$!eB/6ty  
httpConnection.setRequestProperty("User-Agent","NetFox"); !);}zW!  
SU2 (XP]5  
(al7/EhY  
int responseCode=httpConnection.getResponseCode(); QH~/UnV  
if(responseCode>=400) $:/y5zi  
{ ^yH|k@y  
processErrorCode(responseCode); NQ@ EZoJ  
return -2; //-2 represent access is error T?^AllUZQR  
} aW4tJN%!  
o(C({]UO/  
WO^sm Ck  
String sHeader; ./J.OU1  
OQ W#BBet@  
1\kOjF)l  
for(int i=1;;i++)  6<sB   
{ d q"b_pr;  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1}KNzMHk9  
//Utility.log(in.readLine()); (3c,;koRR  
sHeader=httpConnection.getHeaderFieldKey(i); _Vj O [hx  
if(sHeader!=null) :[|`&_D9J  
{ a5L#c=  
if(sHeader.equals("Content-Length")) 'rp(k\ pY  
{ J Y %B:  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qC.jXU?rO  
break; ;QREwT~H  
} >:Xzv  
} ZCbxL.fFz  
else m$pXe<  
break; 3`IDm5  
}  L~I<y;x  
} Y?ZTl762  
catch(IOException e){e.printStackTrace ();} n?!.r c  
catch(Exception e){e.printStackTrace ();} ')Ozz<{  
u0w2v+  
;=*b:y Y  
Utility.log(nFileLength); ) 8st  
zd>[uIOR  
] A9Vh  
return nFileLength; .y+>-[j?B  
} MvL%*("4b  
Q:>;d-D|1  
zP rT0  
//保存下载信息(文件指针位置) `lN1u'(:  
private void write_nPos() 8Tt2T} Y  
{ <)?H98S  
try{ {BY`Wu:w  
output = new DataOutputStream(new FileOutputStream(tmpFile)); q|=tt(}G  
output.writeInt(nStartPos.length); K]N^6ome  
for(int i=0;i<nStartPos.length;i++) 6\OSIxJZF  
{ &"Ua"H)  
// output.writeLong(nPos); K)l{3\9l|  
output.writeLong(fileSplitterFetch.nStartPos); " *kWM  
output.writeLong(fileSplitterFetch.nEndPos); |KplbU0iC  
} TjgX' j  
output.close(); b;9v.MZ4>g  
} 7{v0K"E{  
catch(IOException e){e.printStackTrace ();} @T?:[nPf&F  
catch(Exception e){e.printStackTrace ();} R 4E0avt  
} .<rL2`C[c  
;# {XNq<1  
[WY NA-O  
//读取保存的下载信息(文件指针位置) (<itE3P  
private void read_nPos() ]/JE#  
{ A9p$5jt7  
try{ c c ,]  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); HP*x?|4  
int nCount = input.readInt(); jR }h3!  
nStartPos = new long[nCount]; 1#aOgvf  
nEndPos = new long[nCount]; E)#3*Wlu$  
for(int i=0;i<nStartPos.length;i++) D'|#5>G  
{ vyN =X]p  
nStartPos = input.readLong(); AN$}%t"  
nEndPos = input.readLong(); Itj|0PGd  
} >fdS$,`A  
input.close(); W-7yi`5  
} *ZKfyn$+~  
catch(IOException e){e.printStackTrace ();} u9N?B* &{  
catch(Exception e){e.printStackTrace ();} O 4l[4,`  
} 0N_Ma')i  
nU[ROy5  
h"#^0$f  
private void processErrorCode(int nErrorCode) 0Q]x[;!k  
{ - Kj$A@~x  
System.err.println("Error Code : " + nErrorCode); ,UH`l./3DX  
} o=w& &B  
PKwHq<vAsB  
<4rF3 aB-  
//停止文件下载 ;G;vpl  
public void siteStop() e9k}n\t3  
{ 2ZNTg@o  
bStop = true; 2X]2;W)S;  
for(int i=0;i<nStartPos.length;i++) g#9KG  
fileSplitterFetch.splitterStop(); wgkh} b   
Ju)2J?Xs5  
Ij@YOt  
} ~" }t8`vP1  
} 0-l @U{  
//负责部分文件的抓取 dH&N<  
**FileSplitterFetch.java ?!Rl p/  
*/ k{y@&QNj  
package NetFox; .;/@k%>   
7KuTC%7  
'#u |RsZ  
import java.io.*; DWm$:M4 z  
import java.net.*; A}H)ojG'v  
N$:[`,  
Z^>3}\_v  
public class FileSplitterFetch extends Thread { wH{lp/  
c6E@+xU  
JgYaA*1X  
String sURL; //File URL KB *[b  
long nStartPos; //File Snippet Start Position #E{OOcM  
long nEndPos; //File Snippet End Position ldI;DoE#U1  
int nThreadID; //Thread's ID )h2wwq0]  
boolean bDownOver = false; //Downing is over _9\ ayR>d  
boolean bStop = false; //Stop identical QOy+T6en  
FileAccessI fileAccessI = null; //File Access interface DH)@8)C  
niqiDT/  
D-E30b]e  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _2}i8q:  
{ &wK%p/?  
this.sURL = sURL; C Ij3D"  
this.nStartPos = nStart; c<pr1g  
this.nEndPos = nEnd; [M Z'i/  
nThreadID = id; IUbYw~f3  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2[qO;js  
} X/2Xr(z"k  
{xr4CDP  
LPO3B W  
public void run() `)1_^# k  
{ ZfL\3Mn  
while(nStartPos < nEndPos && !bStop) HMrS::  
{ _4xX}Z;  
Tx`;y|  
"eZNci  
try{ z)]_(zZ^  
URL url = new URL(sURL); 7=Ew[MOmM  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S=eY`,'#R  
httpConnection.setRequestProperty("User-Agent","NetFox"); ~Q>97%  
String sProperty = "bytes="+nStartPos+"-"; #f\U3p  
httpConnection.setRequestProperty("RANGE",sProperty); vZhN% DfY  
Utility.log(sProperty); oPo<F5M]d%  
 x)THeH@  
M=`F $  
InputStream input = httpConnection.getInputStream(); /DQoM@X  
//logResponseHead(httpConnection); 9_ KUUA  
w# ,:L)  
>9uDY+70I3  
byte[] b = new byte[1024]; hi`\3B  
int nRead; FL/@e$AK  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "9&6bBa  
{ T&w3IKb|}  
nStartPos += fileAccessI.write(b,0,nRead); 4F)z-<-b  
//if(nThreadID == 1) .!l#z|/x  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); az?B'|VX  
} QVb @/  
~ NK w}6  
2\CFt;fk  
Utility.log("Thread " + nThreadID + " is over!"); Z[ZqQ` 7N  
bDownOver = true; !@W1d|{lu  
//nPos = fileAccessI.write (b,0,nRead); ~BDVmQa  
} 'fy1'^VPAV  
catch(Exception e){e.printStackTrace ();} ;oH%d;H  
} u6awcn  
} |Y0BnyGK  
]y2(ZTNTs  
R1 hb-  
//打印回应的头信息 7t0\}e  
public void logResponseHead(HttpURLConnection con) R1{ "  
{ mxGa\{D# y  
for(int i=1;;i++) vd9l1"S  
{ `~(KbH=]  
String header=con.getHeaderFieldKey(i); ;rV0  
if(header!=null)  [^8*9?i4  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); tceQn ^|<  
Utility.log(header+" : "+con.getHeaderField(header)); 5m=3{lBi  
else *&% kkbA  
break; 8ooj)  
} 9"I/jd0B  
} TStu)6%`  
TsfOod   
P%ev8]2  
public void splitterStop() #J\ 2/~  
{ ++5W_Ooep  
bStop = true; )o SFHf  
} =V/$&96Q  
: \:jIP  
O<)"k j 7  
} m!$"-nh9  
]9l=geZd%;  
c03A_2%  
/* 4 "@BbVYR  
**FileAccess.java ,fT5I6l  
*//文件访问(定位,写) S^c5  
package NetFox; RI')iz?  
import java.io.*; vaxNF%^~yN  
8N'`kd~6[  
q/6d^&  
public class FileAccessI implements Serializable{ kK16+`\+  
cr27q6_  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vMRM/.  
RandomAccessFile oSavedFile; |F iL1_  
long nPos; i(a2FKLy  
z5=&qo|f9l  
"qu%$L  
public FileAccessI() throws IOException z%hB=V!~91  
{ ;v[F@O~*)  
this("",0); dScit!T"  
} I o|NL6[  
B=(m;A#G  
lw\OsB$  
public FileAccessI(String sName,long nPos) throws IOException ;E,%\<  
{ 0N;Pb(%7UU  
oSavedFile = new RandomAccessFile(sName,"rw"); "e&S*8QhM  
this.nPos = nPos; k =ru) _$2  
oSavedFile.seek(nPos); z%}^9  
} (fUXJ$  
/E2/3z  
:y"Zc1_E  
public synchronized int write(byte[] b,int nStart,int nLen) j\P47q'v#  
{ w3:Y]F.ot  
int n = -1; JY"<b6C^  
try{ #c5G"^)z  
oSavedFile.write(b,nStart,nLen); NFDi2L>Ba  
n = nLen; Y`uL4)hR5  
} A%Pjg1(uX  
catch(IOException e) &\F`M|c  
{ g|9' Lk  
e.printStackTrace (); R.Ao%VT  
} 8*V3g_z  
C o4QWyt:  
_ncqd,&z  
return n; '&I.w p`^  
} t9Ht 5 4  
Sl/[9- a)  
d(jd{L4d  
} w-Y-;*S  
ZL:nohB  
+Tf,2?O  
/* : tu6'X\k  
**SiteInfoBean.java 63#Sf$p{v  
*/ &y[Od{=  
package NetFox; j="{^b  
1[ ME/r  
z:ue]7(.  
public class SiteInfoBean { HpiP"Sl  
C:"Al-  
y[UTuFv~Q  
private String sSiteURL; //Site's URL npkE [JE:  
private String sFilePath; //Saved File's Path yEJ}!/  
private String sFileName; //Saved File's Name EEEYNu/4/  
private int nSplitter; //Count of Splited Downloading File <{Wsh#7}.  
il(dVW  
c`yLn %Of%  
public SiteInfoBean() 9fp1*d  
{//nSplitter的缺省值为5 [[}KCND  
//default value of nSplitter is 5 QmvhmsDL  
this("","","",5); ArDkJ`DE  
} vrXUS9i.  
%G1kkcdH<  
B<SuNbR  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )[|`-M~u  
{ Smzy EMT  
sSiteURL= sURL; g)u ~GA*=  
sFilePath = sPath; iq)4/3"6  
sFileName = sName; y/Fv4<X  
this.nSplitter = nSpiltter; oyZ}JTl( Q  
<5?.s< y$"  
FX`SaY>D  
} h|$.`$  
Kr3L~4>  
9+)5#!0  
public String getSSiteURL() aF7" 4^P  
{ l~kxt2&  
return sSiteURL; (, Il>cR4  
} vn}:$|r$J  
l`G .lM(  
7E*d>:5I  
public void setSSiteURL(String value) R=yn4>I  
{ `rzgC \  
sSiteURL = value; :@a8>i1&  
} hg_@Ui@[z  
&k*sxW'  
wWB-P6  
public String getSFilePath() yANk(  
{ ~W p>tnl  
return sFilePath; Oz<{B]pEul  
} ^  ry   
 w~wpm7  
n@<+D`[.V  
public void setSFilePath(String value) FO#`}? R`  
{ V`sINX  
sFilePath = value; uO8z.  
} DUUQz:?{J  
>0z(+}]3z  
M@ILB-H  
public String getSFileName() bq#*XCt#  
{ G9J+D?'hH  
return sFileName; Sz|;wsF{  
} P~/Gla k  
dr#g[}l'H  
?s/]k#H  
public void setSFileName(String value) ~UA:_7#\M  
{ ;WxE0Q:!~  
sFileName = value; x8 YuX*/I  
} 'o;>6u<u  
V+myGsr`  
oh c/{D2  
public int getNSplitter() 4n_f7'GZg  
{ mcvd/  
return nSplitter; 7~n<%q/6  
} ANh7`AUuO  
~ HFDX@m*  
'au7rX(  
public void setNSplitter(int nCount) N) D;)ZH  
{ w-9M{Es+j  
nSplitter = nCount; Gxx:<`[ON  
} ^GMM%   
} `IL''eJug_  
V`Ve__5;  
Rg@W0Bc)  
/* Y|$3%t  
**Utility.java WfYu-TK *  
*/ *F7ksLH|q  
package NetFox; AG/?LPJ  
OE_;i}58  
|t](4  
public class Utility { /sVy"48-  
1 XsB  
B=?4; l7  
public Utility() E{+V_.tlu  
{ Qv=F'  
N6yPuH  
do0;"O0 (  
} 5H8]N#Y&  
pV`?=[h9  
//线程睡眠 MD`1KC_m  
public static void sleep(int nSecond) uXD?s3Wv  
{ GR6BpV7  
try{ q{v?2v{  
Thread.sleep(nSecond); h^QicvZ  
} IjJO;  
catch(Exception e) x xMV2&,Jq  
{ it?l! ~  
e.printStackTrace (); 2eNA#^T=  
} RE~:+.eB  
} \H <k  
Y v22,|:  
//日志 &)Y26*(`  
public static void log(String sMsg) HAa$ pGb  
{  5`];[M9  
System.err.println(sMsg); E2J.t`H  
} !5 8j xh  
qRy<W  
T#&tf^;  
public static void log(int sMsg) gG5@ KD6k  
{ *htv:Sr  
System.err.println(sMsg); ,|RS]I>X  
} )y8 u+5^  
} ?8 dd^iX/  
;.Dm?J0  
v 809/c*  
/* s'/b&Idf8  
**TestMethod.java #bk[Zj&  
*/ i4"BN,NZ{  
package NetFox; xB.h#x>_`  
rO#WG}E<"  
="X2AuK%1$  
public class TestMethod { Z*,Nt6;e  
mWhQds6  
'L$%)`;e  
public TestMethod() j p g$5jZ  
{ ///xx/weblogic60b2_win.exe sJA` A  
try{ jvGGIb"&1  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ey4RKk,  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %p?+r  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ean_/E  
fileFetch.start(); K7o!,['W  
} f;";P  
catch(Exception e){e.printStackTrace ();} aB@D-Y"HO  
{{'GR"D  
=Yd{PZ*fR  
} Hrz #So\#  
9/[1a_ r  
|"7F`M96I  
public static void main(String[] args) OB-gH3:  
{ *>b*I4dz  
new TestMethod(); |Dz$OZP  
} u7L!&/6On  
} >\J({/ #O  
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
如果您提交过一次失败了,可以用”恢复数据”来恢复帖子内容
认证码:
验证问题:
10+5=?,请输入中文答案:十五