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
  • 7119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
/* 34U~7P r9  
**SiteFileFetch.java u/zC$L3B(  
*/ 8,R]R=  
package NetFox; BYY>;>V  
import java.io.*; *0U(nCT&m  
import java.net.*; :J"e{|g',  
J kA~Ol  
i~2>kxf;K1  
public class SiteFileFetch extends Thread { 7+ysE  
V>nY?  
V7^?jck  
SiteInfoBean siteInfoBean = null; //文件信息Bean My ^pQ]@  
long[] nStartPos; //开始位置 YT_kMy>  
long[] nEndPos; //结束位置 ;?&;I!  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 A T%0i  
long nFileLength; //文件长度 0L6L_;o  
boolean bFirst = true; //是否第一次取文件 ;gc 2vDMv  
boolean bStop = false; //停止标志 1a' JNe$  
File tmpFile; //文件下载的临时信息 [9L(4F20  
DataOutputStream output; //输出到文件的输出流 }'{(rU  
oqE -q\!H  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 8RK\B%UW  
public SiteFileFetch(SiteInfoBean bean) throws IOException ''6"Xi|5  
{ brFOQU?  
siteInfoBean = bean; DK- =Q~`!  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); }}]Y mf  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); QZ`<+"a0  
if(tmpFile.exists ()) )SQ g  
{ R|vF*0)>W  
bFirst = false; "Vh(%N`6  
read_nPos(); #4Z$O(  
} "~;jFB8  
else :Cuae?O,  
{ J h"]iN  
nStartPos = new long[bean.getNSplitter()]; i^> RjR  
nEndPos = new long[bean.getNSplitter()]; c:iMbJOn#  
} +VeLd+Q}  
HP8pEo0Y  
p?`N<ykF<  
/j^zHrLN  
} md_Ld /  
( u _ sz  
D^u{zZy@e  
public void run() 25TEbp[dy  
{ h~1QmEat  
//获得文件长度 D3Mce|t^  
//分割文件 "~ `-Jkm   
//实例FileSplitterFetch 3ZVfZf  
//启动FileSplitterFetch线程 Hy6Np62  
//等待子线程返回 tY#^3ac  
try{ [ M'1aBx^  
if(bFirst) WZMsmhU@T  
{ HqgH\  
nFileLength = getFileSize(); V~wmGp.e  
if(nFileLength == -1) v:>P;\]r9M  
{ 7-LeJRB  
System.err.println("File Length is not known!"); M{H&5 9v  
} ^>" ?!lv  
else if(nFileLength == -2) k (R4-"@  
{ 1Y`MJ \9  
System.err.println("File is not access!"); pg<>Ow5,~l  
} -"<f(  
else #7>CLjI  
{ ovohl<o\  
for(int i=0;i<nStartPos.length;i++) M]'AA Uo8  
{ XVfQscZe  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); }u&JX  
} &td#m"wI  
for(int i=0;i<nEndPos.length-1;i++) f[RnL#*xJU  
{ n*1UNQp@]O  
nEndPos = nStartPos[i+1]; m|k,8guG  
} :o:??tqw  
nEndPos[nEndPos.length-1] = nFileLength; Yem\`; *  
} ?,NAihN]  
} _e'mG'P(  
2S;zze7)  
ke0W?  
//启动子线程 ".\(A f2  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; j;3o9!.s:  
for(int i=0;i<nStartPos.length;i++) l.BNe)1!22  
{ B_S3}g<~  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `+uXL9mo  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D6t]E)FH  
nStartPos,nEndPos,i); 9 2EMDKJ  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cMv3` $  
fileSplitterFetch.start(); `FwAlYJK  
} J 0 P  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8`2K=`]ES+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); iCS/~[  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", dUZ&Ty^{  
nEndPos = " + nFileLength); d1-p];&  
// fileSplitterFetch[nPos.length-1].start(); A@ME7^w7  
?<;<#JN  
zvD5i,I  
//等待子线程结束 zYL^e @  
//int count = 0; \K6J{;#L  
//是否结束while循环 gm DC,"Y<  
boolean breakWhile = false; s,Swlo7D!  
m 5Kx}H~  
6,PL zZ5  
while(!bStop) St`m52V(5X  
{ 9o`3g@6z  
write_nPos(); ${wE5^ky  
Utility.sleep(500); n&]w* (,  
breakWhile = true; BXY'%8q _a  
keOW{:^i  
Vd4osBu{fY  
for(int i=0;i<nStartPos.length;i++) $w\, ."y  
{ M6iKl  
if(!fileSplitterFetch.bDownOver) k:Q<Uanc[  
{ |xm|Q(PG  
breakWhile = false; I>a a'em  
break; B5G$o{WM  
} FS:WbFmc  
} 3)Y:c2  
if(breakWhile) $ *A3p  
break; G.8b\E~  
=6&D4~R  
cmI#R1\  
//count++; b`zf&Mn  
//if(count>4) 7g9^Jn  
// siteStop(); ;kBies>V  
} 5g5NTm`=<  
 t;Om9  
R:N-y."La.  
System.err.println("文件下载结束!"); ISew]R2  
} sfE8b/Z8  
catch(Exception e){e.printStackTrace ();} lvi:I+VgA  
} avu,o   
,~(}lvqVH  
$:!T/*p*  
//获得文件长度 Bq_P?Q+\  
public long getFileSize() Z;D3lbqE  
{ -^v}T/Kl#  
int nFileLength = -1; C&kl*nO  
try{ :'~ gLW>j  
URL url = new URL(siteInfoBean.getSSiteURL()); &tCtCk%{j  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X>7]g670@  
httpConnection.setRequestProperty("User-Agent","NetFox"); J|S^K kC  
C} _:K)5q  
RI3{>|*  
int responseCode=httpConnection.getResponseCode(); W+e*(W|d6  
if(responseCode>=400) 4&hqeY3  
{ y51D-vj  
processErrorCode(responseCode); -i5g 8t'  
return -2; //-2 represent access is error 2-!Mao"^  
} =@=R)C4f*  
\N+Ta:U1P  
Gj`Y2X2r  
String sHeader; e-3pg?M  
i03}f%JnuO  
ZM`P~N1?)g  
for(int i=1;;i++) )+4}Ix/q  
{ %L>nXj  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Pl& `&N;  
//Utility.log(in.readLine()); '8kjTf#g<l  
sHeader=httpConnection.getHeaderFieldKey(i); "UGj4^1f  
if(sHeader!=null) #aY<J:Nx  
{ #r)1<}_e#  
if(sHeader.equals("Content-Length")) ~Z6p3# !o  
{ Ny,A#-?  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Bye@5D  
break; tO>OD#  
} k5QD5/Ej  
} >"g<-!p@  
else ivz9R'  
break; y{Y+2}Dv/  
} A2:){`Mw  
} Jo aDX ,  
catch(IOException e){e.printStackTrace ();} 7h9[-d6  
catch(Exception e){e.printStackTrace ();} 3hf ;4Mb  
fwv T2G4  
6Y_O^f  
Utility.log(nFileLength); J*~2 :{=%  
6+nMH +[  
dwbY"t[9  
return nFileLength; %^?3s5PXD  
} NU&^7[!yl  
pebx#}]p-  
Y:!/4GF  
//保存下载信息(文件指针位置) z5&%T}$tJ  
private void write_nPos() tZu*Asx7  
{ M|5]#2J_2  
try{ 5*wApu{2A  
output = new DataOutputStream(new FileOutputStream(tmpFile)); acYoOW1G  
output.writeInt(nStartPos.length); i=X*  
for(int i=0;i<nStartPos.length;i++) AK s39U'  
{ 2u*h*/  
// output.writeLong(nPos); [mf7>M`p]@  
output.writeLong(fileSplitterFetch.nStartPos); t>6x)2,TC  
output.writeLong(fileSplitterFetch.nEndPos); Dj ]Hgg  
} (o6[4( G  
output.close(); $dZ>bXUw:  
} /x:(SR2,  
catch(IOException e){e.printStackTrace ();} "gbnLKs  
catch(Exception e){e.printStackTrace ();} cbu nq"  
} VU`z|nBW@  
2 ]DCF  
]o[X+;Tj|  
//读取保存的下载信息(文件指针位置) %%+mWz a  
private void read_nPos() 3$$5Mk(&  
{ A eGG  
try{ \at-"[.  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <nw <v9Z  
int nCount = input.readInt(); <=m 30{;f  
nStartPos = new long[nCount]; cbh#E)[ '  
nEndPos = new long[nCount]; @!":(@3[  
for(int i=0;i<nStartPos.length;i++) bQXc IIa{  
{ ;h,R?mU  
nStartPos = input.readLong(); OC?Zw@  
nEndPos = input.readLong(); zr3q>]oma  
} 4j. |Y  
input.close(); Esz1uty  
} (zS2Ndp  
catch(IOException e){e.printStackTrace ();} y|e2j&m  
catch(Exception e){e.printStackTrace ();} 4V228>9w  
} JtYYT/PB  
Wkg*J3O  
'NT#(m%  
private void processErrorCode(int nErrorCode) L,b|Iq  
{ Tsm1C#6 Y*  
System.err.println("Error Code : " + nErrorCode); to!mz\F  
} ^ea RgNz  
nW $A^  
Avs7(-L+s  
//停止文件下载 Y)Znb;`?a  
public void siteStop() C(F1VS  
{ fuNl4BU  
bStop = true; aQ!9#d_D  
for(int i=0;i<nStartPos.length;i++) rV8(ia  
fileSplitterFetch.splitterStop(); i O%Zd[  
m\*&2Na  
b?Cmc  
} 1-6gB@cvQ  
} ER~T'-YMS  
//负责部分文件的抓取 E/wQ+rv  
**FileSplitterFetch.java TnN^2:cU  
*/ kf+JM/  
package NetFox; q4sl=`L5Sp  
$xRo<,OV+  
6-*~ t8  
import java.io.*; xZ^ywa_  
import java.net.*; QO5OnYh  
Jj=yG"$!  
f![xn2T  
public class FileSplitterFetch extends Thread { b(q$j/~ zb  
Nl~Z,hT$*  
*oEv,I_  
String sURL; //File URL ]{K5zSK  
long nStartPos; //File Snippet Start Position ]~?S~l%  
long nEndPos; //File Snippet End Position D-Bv(/Pz]$  
int nThreadID; //Thread's ID CCuxC9i7  
boolean bDownOver = false; //Downing is over ,(j>)g2Ob  
boolean bStop = false; //Stop identical gXq!a|eH  
FileAccessI fileAccessI = null; //File Access interface 4|zd84g  
r> Fec  
?@_v,,|  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jmRhAJV  
{ rU; g0'4e  
this.sURL = sURL; IM[54_I  
this.nStartPos = nStart; :0nK`$'  
this.nEndPos = nEnd; Ezi' 2Sc  
nThreadID = id; Vn)%C_-]A  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 jZa25Z00  
} hA@zoIoe  
D35m5+=I  
jz %;4e~t  
public void run() I_:t}3s  
{ =8O}t+U  
while(nStartPos < nEndPos && !bStop) 40 A&#u9o  
{ 86/.8  
2y^U k,g  
"=9-i-K9B  
try{ cE^kpnVq|<  
URL url = new URL(sURL); A)OdQFet(  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D._{E*vg  
httpConnection.setRequestProperty("User-Agent","NetFox"); l &}piC  
String sProperty = "bytes="+nStartPos+"-"; \^yXc*C  
httpConnection.setRequestProperty("RANGE",sProperty); IS-}:~Pi  
Utility.log(sProperty); \.5F](:  
 NI^{$QMj  
dI!8S  
InputStream input = httpConnection.getInputStream(); I9;xzES  
//logResponseHead(httpConnection); OSU{8.  
1d`cTaQ-  
37#cx)p^f  
byte[] b = new byte[1024]; =ntft SH  
int nRead; hl`u"?rg  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) QQ*gFP.Ao  
{ >Q&CgGpW$  
nStartPos += fileAccessI.write(b,0,nRead); : -E,   
//if(nThreadID == 1) I[@ts!YD  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5;}2[3}[  
} H4W1\u  
-jFP7tEv  
|0lLl^zp  
Utility.log("Thread " + nThreadID + " is over!"); g- XKP  
bDownOver = true; p*Xix%#6  
//nPos = fileAccessI.write (b,0,nRead); *E.LP1xP  
} !-7_ +v>  
catch(Exception e){e.printStackTrace ();} ]7*kWc2  
} ;r3}g"D@  
} iZC>)&ax  
\/n+j!  
_wmI(+_  
//打印回应的头信息 2.ew^D#  
public void logResponseHead(HttpURLConnection con) Mw+v"l&mU  
{ h 5Hr[E1  
for(int i=1;;i++) [O(m/  
{ |88CBiu}  
String header=con.getHeaderFieldKey(i); .wP/ai>}  
if(header!=null) Oc#>QZ3  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3EI]bmi~  
Utility.log(header+" : "+con.getHeaderField(header)); \Y+")  
else Y|_O8[  
break; JwB"\&'1ZS  
} Z/gsCYS3F  
} F.68iN}  
x7H A722w  
S#mK Pi+3  
public void splitterStop() p3 e|j  
{ f9a$$nb3`  
bStop = true; Zb"jB$58  
} )(lJT&e  
drI\iae{^  
IytDvz*|  
} TU%bOAKF\  
M1EOnq4-  
GB =bG%Tb  
/* >nK%^T  
**FileAccess.java L:pUvcAc?  
*//文件访问(定位,写) Q(e{~ ]*  
package NetFox; x)_r@l`$ix  
import java.io.*; J+|/-{g  
V 9Hl1\j^  
}vY.EEy!  
public class FileAccessI implements Serializable{ O@wK[(w^  
AuXs B  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5B?i(2&#  
RandomAccessFile oSavedFile; !3V{2-y$-  
long nPos; *{|$FQnR>(  
'60//"9>k/  
m]P/if7  
public FileAccessI() throws IOException ?A&%Cwj  
{ vY_eDJ~'  
this("",0); bcn7,ht  
} ' %&z.{  
;{gT=,KQ`  
, D"]y~~I5  
public FileAccessI(String sName,long nPos) throws IOException *VDVC0R  
{ =k_UjwgN^  
oSavedFile = new RandomAccessFile(sName,"rw"); G?ig1PB"#  
this.nPos = nPos; ?-,6<K1  
oSavedFile.seek(nPos); ({ k7#1 h8  
} yLqF ,pvO  
i ?-Y  
`*k@4.J{  
public synchronized int write(byte[] b,int nStart,int nLen) (:7a&2/M  
{ vBoO'l9'M  
int n = -1; CN\=9Rvs  
try{ oM-[B h]A  
oSavedFile.write(b,nStart,nLen); `tVy_/3(9  
n = nLen; U=QA  e  
} Ww`&i  
catch(IOException e) v2>Z^  
{ BIj   
e.printStackTrace (); n NQ-"t  
} &d,Wy"WPi  
`0@z"D5c  
zJC EA  
return n; fGarUV  
} iRve)   
b-%l-u  
gDC2 >nV  
} Q0>q:aj\  
(a#pvEY  
ArXl=s';s4  
/* onnugj3  
**SiteInfoBean.java 5@f5S0 Y  
*/ mb{q(WEPP  
package NetFox; \fi}Q\|C  
d.r Y-k  
0*yJ %  
public class SiteInfoBean { doLNz4W  
niWx^gKb$  
,YB1 y)x  
private String sSiteURL; //Site's URL eY}V9*.v  
private String sFilePath; //Saved File's Path @i1q]0  
private String sFileName; //Saved File's Name fp;a5||5  
private int nSplitter; //Count of Splited Downloading File V^rW?Do  
]sL45k2W  
s|2}2<+  
public SiteInfoBean() |GuEGmR  
{//nSplitter的缺省值为5 GOVAb'  
//default value of nSplitter is 5 2w4MJ,Uw  
this("","","",5); Gru ALx7  
} F,pCR7o>  
i0ybJOa4  
$E.XOpl&I  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +)gB9DoK  
{ }N,>A-P  
sSiteURL= sURL; m =k%,J_  
sFilePath = sPath; (oYW]c}G,  
sFileName = sName; 6N3@!xtpi  
this.nSplitter = nSpiltter; '{VM> Q  
GYoseqZM  
[hnK/4!  
} w~N-W8xNR  
<'2u a  
GAp!nix6h  
public String getSSiteURL() _9kIRmT{  
{ 784;]wdy\  
return sSiteURL; YoAg  
} ikHOqJ-,m  
98UlNP  
)4uq iA6  
public void setSSiteURL(String value) N-%#\rPq.  
{ !01i%W'  
sSiteURL = value; , N 344y  
} d?7BxYaa  
%6i=lyH-  
rPO}6lsc  
public String getSFilePath() C3.=GRg~l  
{ 4B$bj `h  
return sFilePath; .bfST.OA  
} 6"%2,`Nu  
voh^|(:(TH  
>'Hx1;  
public void setSFilePath(String value) or.\)(m#(  
{ 7K:FeW'N  
sFilePath = value; bQ.nFa']  
} xwOE+  
Q|//Z  
P` ]ps?l  
public String getSFileName() a}yR p  
{ 4J8Dh;a`  
return sFileName; q+%!<]7X  
} "TFwHe3C4  
v, 0<9!'v  
OG}KqG!n  
public void setSFileName(String value) 6[+j'pW?  
{ ^ZVO ql&  
sFileName = value; ^A#x<J+  
} 8&?p  
{(0Id!  
)_Iz>)  
public int getNSplitter() -TZ^~s  
{ ?i%nMlcc  
return nSplitter; d?}hCo=/Xq  
} }.t^D|  
2Fq=jOA)z$  
8]]@S"ZM,\  
public void setNSplitter(int nCount) pN+I]NgQ  
{ H &fTh  
nSplitter = nCount; %omu  
} |0]YA  
} 453 }S  
K1-+A2snhV  
WL/5 oj  
/* vX 1W@s  
**Utility.java nF|Oy0  
*/ 9C=~1>S  
package NetFox; |?yE^$a  
g/B\ObY  
-)>(8f  
public class Utility { J@gm@ jLc  
$>![wZ3  
F {/>u(@3  
public Utility() yWmrdvL  
{ Cy6%S).c  
6"%@ L{UQ  
y:C)%cv}*  
} l-cW;b~  
?0uOR *y'  
//线程睡眠 R~$hWu}}  
public static void sleep(int nSecond) {x9j_/R  
{ F$[)Bd/"  
try{ %6N)G!P  
Thread.sleep(nSecond); *h:D|4oJ(  
} ,!r@9T  
catch(Exception e) <5M_EJp  
{ 9QC< E|  
e.printStackTrace (); \FVNXU MU  
} p1klLX  
} ma1 (EJ/  
Etw~*  
//日志 $,.3&zsy  
public static void log(String sMsg) zUJx&5/  
{ 0u>yT?jP  
System.err.println(sMsg); \|blRm;  
} Qg[heND  
UmYD]  
b-2pzcK{#  
public static void log(int sMsg) bB y'v/  
{ 1k$2LQ  
System.err.println(sMsg);  ccRlql(  
} ";756'>  
} 0T(O'v}.  
@51z-T  
vf6`s\6  
/* NWw<B3aL  
**TestMethod.java 15o9CaQw4"  
*/ yq1Gqbh l  
package NetFox; EK^JLvyT  
eR7qE) h  
L7X7Zt8%  
public class TestMethod { n'q aR<bY  
>y]?MGk  
H3!,d`D.N  
public TestMethod()  o1 jk=  
{ ///xx/weblogic60b2_win.exe 3Wjq>\  
try{ n; Lo  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); kZJt ~}  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); T@B"BoKU  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]^Sd9ba  
fileFetch.start(); k&WUv0  
} cR,'o'V/  
catch(Exception e){e.printStackTrace ();} ~ &t!$  
+G<}JJ'V  
-b@v0%Q2M*  
} z`c%?_EK  
_TtX`b_Z  
2O?Vr" A  
public static void main(String[] args) $5ZR [\$  
{ xylpiSJ  
new TestMethod(); jn.R.}TT  
} 98X!uh'  
} 1[26w_B3  
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
批量上传需要先选择文件,再选择上传
认证码:
验证问题:
10+5=?,请输入中文答案:十五