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
  • 11859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
/* _(}{=:M?  
**SiteFileFetch.java =8r%zLDw  
*/ 3hOiHO ;  
package NetFox; DHO6&8S  
import java.io.*; 9=j"kXFf  
import java.net.*; ZkW,  
a{7>7%[  
bUf2uWy7  
public class SiteFileFetch extends Thread { [<Wo7G1s  
lCDu,r;\  
2Y)3Ue  
SiteInfoBean siteInfoBean = null; //文件信息Bean *7C t#GC  
long[] nStartPos; //开始位置 +s:!\(BM  
long[] nEndPos; //结束位置 }@Ij}Ab>  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 a W`q  
long nFileLength; //文件长度 _-&\~w  
boolean bFirst = true; //是否第一次取文件 ~Cx07I_lf  
boolean bStop = false; //停止标志 YK/?~p9:  
File tmpFile; //文件下载的临时信息 |hjm^{!TpW  
DataOutputStream output; //输出到文件的输出流 u=h:d+rq@  
$ZD1_sJ.  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) nk,X6o9%  
public SiteFileFetch(SiteInfoBean bean) throws IOException :A\8#]3  
{ ~a:0Q{>a  
siteInfoBean = bean; r^mP'#  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 8,pnm  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); XO+^q9  
if(tmpFile.exists ()) l+'@y (}Q  
{ K14e"w%6rs  
bFirst = false; <FIc!  
read_nPos(); ZR<T\w  
} $DZ\61  
else _\YBB=Os  
{ 66*/"dBwm  
nStartPos = new long[bean.getNSplitter()]; P%A^TD|  
nEndPos = new long[bean.getNSplitter()]; IWvLt  
} epsh&)5a*  
4=S.U`t7  
_-$"F>  
lC Bb0k2  
} ?(el6J}  
%|$h<~  
B] dvX  
public void run() tCAh?nR  
{ 6 eqxwj{S[  
//获得文件长度 f"zXiUV  
//分割文件 &v7$*n27  
//实例FileSplitterFetch cXiNO ke&  
//启动FileSplitterFetch线程 :?%$={m  
//等待子线程返回 Hn5:*;N  
try{ l2"{uCcA  
if(bFirst) +jePp_3$O  
{  ")MjR1p  
nFileLength = getFileSize(); > 4>!zZ  
if(nFileLength == -1) ld8E!t[  
{ {<{ O!  
System.err.println("File Length is not known!"); !63p?Q=  
} ct+ ;W  
else if(nFileLength == -2) g5X;]%:  
{ FS7 _ldD  
System.err.println("File is not access!"); >J+'hm@  
} C?jk#T  
else ;/w-7O:  
{ Q H:k5V~  
for(int i=0;i<nStartPos.length;i++) _KBN  
{ j^#4!Ue  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 9MQ!5Zn  
} e^)+bmh  
for(int i=0;i<nEndPos.length-1;i++) N t]YhO  
{ q}[g/%  
nEndPos = nStartPos[i+1]; W($}G_j[B1  
} 4RCD<7  
nEndPos[nEndPos.length-1] = nFileLength; SJb+:L>  
} eg Ml(~D  
} RKoM49W  
`)Z"||8K  
 J jRz<T;  
//启动子线程 f%fD>a  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2Wwzcvs@  
for(int i=0;i<nStartPos.length;i++) @v^;,cu'8  
{ -`nQa$N-  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(),  xE.K  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xj8 yQ Y1  
nStartPos,nEndPos,i); 0$)uOUVJ  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HBHDu;u  
fileSplitterFetch.start(); \$GM4:R D  
} 5VD(fW[OW]  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !n9H[QP^9  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 04ZP\  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }71a3EUK  
nEndPos = " + nFileLength); \ng!qN  
// fileSplitterFetch[nPos.length-1].start(); `}t<5_  
+XV7W=  
Y+vG ]?D  
//等待子线程结束 Dv~W!T i  
//int count = 0; 0LEJnl  
//是否结束while循环 84g$V}mp  
boolean breakWhile = false; jc rLUs+\  
Jg} w{,  
'sb&xj`d  
while(!bStop) a;a^- n|D  
{ !'|^`u=eL  
write_nPos(); cP#vzFB0>  
Utility.sleep(500); Jbv66)0M  
breakWhile = true; cAFYEx/(  
M)sM G C  
$*N^ bj  
for(int i=0;i<nStartPos.length;i++) *AK{GfP_  
{ Kvx~2ZMx6  
if(!fileSplitterFetch.bDownOver) .nDB{@#  
{ Z:>)5Z{'  
breakWhile = false; t}FwS6u  
break; n hT%_se4  
} mhh^kwW  
} fXNl27c-  
if(breakWhile) ca )n*SD  
break; u^2)oL  
kA c8[Hn  
[;6,lI}  
//count++; C_CUk d[  
//if(count>4) (*qMs)~]B  
// siteStop(); fcaUj9qN  
} *CtWDUxSdW  
vwF#;jj\  
O_vCZW a3  
System.err.println("文件下载结束!"); KHnq%#  
} tqo k.h  
catch(Exception e){e.printStackTrace ();} f/"? (7F  
} 73C7g< Mx  
Fsdp"X.  
~ 9Xs=S!  
//获得文件长度 +95: O 8  
public long getFileSize() V46=48K.  
{ [f._w~  
int nFileLength = -1; 3[_zz;Y*d  
try{ 1u`{yl*+?  
URL url = new URL(siteInfoBean.getSSiteURL()); +\s32o zg  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6gr?#D -F  
httpConnection.setRequestProperty("User-Agent","NetFox"); MSQz,nn  
{>EM=ZZfg  
hCpX# rg?  
int responseCode=httpConnection.getResponseCode(); nDG41)|  
if(responseCode>=400) W20qn>{z  
{ Qqm$Jl!  
processErrorCode(responseCode); KOv?p@d  
return -2; //-2 represent access is error @wVq%GG}  
} P5?M"j0/^  
qoZUX3{  
6h5DvSO  
String sHeader; $3yzB9\a"  
%imI.6   
ve3-GWT{C  
for(int i=1;;i++) tBB\^xq:  
{ Hl|EySno  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -F->l5  
//Utility.log(in.readLine()); cc0e(\  
sHeader=httpConnection.getHeaderFieldKey(i); {tKi8O^Rb  
if(sHeader!=null) %[l#S*)~  
{ au+6ookT  
if(sHeader.equals("Content-Length")) a ]b%v9  
{ @Z+(J:Grm5  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $!LL  
break; Uo]x6j<  
} F/ si =%  
} 5w9oMM {  
else :Vnus @#r  
break; T[(4z@d`5  
} a_V.mu6h6p  
} S\jIs[Dz  
catch(IOException e){e.printStackTrace ();} 9coN >y  
catch(Exception e){e.printStackTrace ();} }LA7ku  
+$CO  
(_ TKDx_  
Utility.log(nFileLength); qA;!Pql`  
y+aL5$x6  
b<E0|VW  
return nFileLength; 9JtPP  
} EJByYk   
M[:},?ah0  
[&MhAzF  
//保存下载信息(文件指针位置) -dO9y=?t  
private void write_nPos() .9uw@ Eq  
{ `VL<pqPP  
try{ >Y)FoHa+/  
output = new DataOutputStream(new FileOutputStream(tmpFile)); &al\8  
output.writeInt(nStartPos.length); SbYs a  
for(int i=0;i<nStartPos.length;i++) mo*ClU7  
{ +)<H,?/  
// output.writeLong(nPos); b%_[\((  
output.writeLong(fileSplitterFetch.nStartPos); +Rq7m]  
output.writeLong(fileSplitterFetch.nEndPos); "k> ;K,:  
} ~IQ2;A  
output.close(); IEj=pI   
} ,b${3*PPQ  
catch(IOException e){e.printStackTrace ();} |M$ESj4@  
catch(Exception e){e.printStackTrace ();} w+Oo-AGNH  
} k2Dq~zn  
@ C"w 1}  
;p8,=w  
//读取保存的下载信息(文件指针位置) ~i5t1  
private void read_nPos() =N?K)QD`  
{ ;n2b$MB?nM  
try{ tj< 0q<is  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); p+.{"%  
int nCount = input.readInt(); 6>e YG <y{  
nStartPos = new long[nCount]; {)y8Y9G  
nEndPos = new long[nCount]; F#>^S9Gml  
for(int i=0;i<nStartPos.length;i++) 6v(;dolBIw  
{ =JDa[_lpN  
nStartPos = input.readLong(); sqjv3=}  
nEndPos = input.readLong(); ,0fYB*jk  
} :/6gGU>pu  
input.close(); dt1,! sHn  
} )K>2  
catch(IOException e){e.printStackTrace ();} yS"; q  
catch(Exception e){e.printStackTrace ();} |)pgUI2O[  
}  gU%R9  
fs3jPHZJ#  
}DzN-g<K  
private void processErrorCode(int nErrorCode) ;FH_qF`.  
{ i9B1/?^W&  
System.err.println("Error Code : " + nErrorCode); iTpK:p X  
} s]@k,%  
<uL0 M`u3  
15U[F0b  
//停止文件下载 >&DNxw  
public void siteStop() @;P\`[(*  
{ 0o*  
bStop = true; ;Y"*Z2U  
for(int i=0;i<nStartPos.length;i++) d_!l RQ^N  
fileSplitterFetch.splitterStop(); 5;yVA  
Y:3\z?oV[  
FZJyqqA$_  
} \-scGemH  
} qE)G;Y<,1  
//负责部分文件的抓取 <CM}g4Y  
**FileSplitterFetch.java w@Gk#  
*/ .:?cU#.  
package NetFox; 6H:'_|G  
Xw<5VIAHm;  
^[u*m%UB  
import java.io.*; B>{\qj)%  
import java.net.*; F3,djZq  
KRN{Ath.  
2Hj;o  
public class FileSplitterFetch extends Thread { ?:1)=I<A4  
]Yd7  
d*(wU>J '  
String sURL; //File URL \[5mBuk  
long nStartPos; //File Snippet Start Position +/Vi"  
long nEndPos; //File Snippet End Position [-*8 S1  
int nThreadID; //Thread's ID K" U!SWv  
boolean bDownOver = false; //Downing is over p(-EtxP  
boolean bStop = false; //Stop identical ]heVR&bQ  
FileAccessI fileAccessI = null; //File Access interface xi=0 kO  
(/^?$~m"  
GPizR|}h  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~$ Po3]{s  
{ E^Ch;)j|  
this.sURL = sURL; mN l[D  
this.nStartPos = nStart; PZvc4  
this.nEndPos = nEnd; 3s?ZyQy  
nThreadID = id; KYyoN  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Q@|"xKa  
} @NiLKcL#  
\Unawv~  
<Qr*!-Kc6  
public void run() elR1NhB|p  
{ -]-0]*oAp  
while(nStartPos < nEndPos && !bStop) &> _aY #  
{ m;nH v  
9ei<ou_s  
[VLq/lg*  
try{ ;dtA-EfOZ  
URL url = new URL(sURL); fLeHn,*,"  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q,_E HPc  
httpConnection.setRequestProperty("User-Agent","NetFox"); N?8nlrDQ  
String sProperty = "bytes="+nStartPos+"-"; Q-A_8  
httpConnection.setRequestProperty("RANGE",sProperty); iaQfxQP1w%  
Utility.log(sProperty); EiP N44(  
@My RcC  
&xvNR=K[`  
InputStream input = httpConnection.getInputStream(); E:O/=cT  
//logResponseHead(httpConnection); e\O625  
\ KsKb0sM  
e A3 NyL  
byte[] b = new byte[1024]; l: kW|  
int nRead; GY5JPl  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xOr"3;^  
{ O>I%O^  
nStartPos += fileAccessI.write(b,0,nRead); =(~*8hJ  
//if(nThreadID == 1) a^^OI|?  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {u0sbb(  
} <WbO&;%  
S;/pm$?/  
!]9qQ7+R%  
Utility.log("Thread " + nThreadID + " is over!"); tR 4+]K  
bDownOver = true; >p#_ L^oZ%  
//nPos = fileAccessI.write (b,0,nRead); OlptO60{ ]  
} D+N@l"U{  
catch(Exception e){e.printStackTrace ();} _RS CyV  
} fGW~xul_  
} Ic^ (6  
.Wi%V"  
[w-# !X2y  
//打印回应的头信息 ?!$Dr0r  
public void logResponseHead(HttpURLConnection con) 0'Qvis[kt  
{ !s ! el;G  
for(int i=1;;i++) KNN$+[_;H4  
{ hD7vjg& Z  
String header=con.getHeaderFieldKey(i); ^jcVJpyT@R  
if(header!=null) "Er8RUJA  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "HwlN_PA  
Utility.log(header+" : "+con.getHeaderField(header)); =EH/~NGk  
else a[,p1}!_  
break; l)~$/#k  
} h#dfhcU>  
} 5Vdy:l  
1(_[awBx  
Su[(IMw  
public void splitterStop() E$A=*-u  
{ @7;}6,)  
bStop = true; h`eHoKJ#w  
} |eFaOL|  
'*Tt$0#o  
ynf!1!4  
} &OkPO|  
_PQk<QZ  
<]_[o:nOP  
/* ^rO!-  
**FileAccess.java }[PC YnS  
*//文件访问(定位,写) 7AqbfLO  
package NetFox; z5D*UOy5M  
import java.io.*; $"}[\>e*{  
e2>AL  
*.VNyay  
public class FileAccessI implements Serializable{ `Tk~?aY  
-i_XP]b&  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 jLY$P<u?%P  
RandomAccessFile oSavedFile; f)V6VNW.3  
long nPos; d+5v[x~'  
$" =3e]<  
ka{!' ^  
public FileAccessI() throws IOException Mhb~wDQl  
{ k9NHdi7&2  
this("",0); [r9HYju =  
} : w>R|]  
X`-o0HG  
L)S V?FBx  
public FileAccessI(String sName,long nPos) throws IOException -6X+:r`>u  
{ zz<o4b R  
oSavedFile = new RandomAccessFile(sName,"rw"); T-x9IoE  
this.nPos = nPos; l1 _"9a%H  
oSavedFile.seek(nPos); ux 17q>G  
} T[g(S0dz  
DK'S4%;Sp  
\C2HeA\#SW  
public synchronized int write(byte[] b,int nStart,int nLen) CHjm7  
{ ,w=u?  
int n = -1; 6\VZ 6oS  
try{ A6E~GJa  
oSavedFile.write(b,nStart,nLen); -D1 A  
n = nLen; JL<<EPC  
} nU6UjC|3  
catch(IOException e) 8%a ^j\L  
{ zyt >(A1  
e.printStackTrace (); oh9L2"  
} 5yj6MaqJ  
.ezZ+@LI+#  
_fHj8- s/  
return n; ;E!] /oY<  
} ER}5`*X{  
%WX^']p  
Id>I.e4  
} Kw:%B|B<T  
/1bQ RI^\  
5Q8s{WQ  
/* )t:8;;W@Ir  
**SiteInfoBean.java 2r]o>X  
*/ :2XX~|  
package NetFox; sv#b5,>9  
WD*z..`  
WY5HmNX3E  
public class SiteInfoBean { 6uk}4bdvq  
TQ%F\@"  
*<h)q)HS  
private String sSiteURL; //Site's URL ~~m(CJ4S  
private String sFilePath; //Saved File's Path =8"xQ>D62  
private String sFileName; //Saved File's Name ~0}d=d5g  
private int nSplitter; //Count of Splited Downloading File ^7t1'A8e<  
*/|<5X;xIA  
o!c~"  
public SiteInfoBean() 'TA !JB+  
{//nSplitter的缺省值为5 m6A\R KJ'  
//default value of nSplitter is 5 6 .[3N~pq  
this("","","",5); ;hEeFJ=/G  
} R+=wSG]  
$' ::51  
C AN1~  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) nV8iYBBym  
{ ,s:viXk  
sSiteURL= sURL; _NpxV'E  
sFilePath = sPath; U8,pe;/ln`  
sFileName = sName; e+<9Sh7&  
this.nSplitter = nSpiltter; 5ci1ce  
s3K!~v\L]  
'tjqfR  
} k/BlkjlNE  
lvLz){  
p9S>H  
public String getSSiteURL() [| N73m,&  
{ !\^W*nQ>l  
return sSiteURL; dx$+,R~y  
} CW.T`F  
!;${2Q  
ocZ^rqo2w  
public void setSSiteURL(String value) [N<rPHT  
{ +c__U Qx  
sSiteURL = value; L@ejFXQg  
} \Xr*1DI<  
),^pi?  
b&AeIU}&  
public String getSFilePath() K}'?#a(aX=  
{ ySF^^X $J  
return sFilePath; }KEr@h,N  
} y'non0P.  
>Pvz5Hf/wW  
;krIuk-  
public void setSFilePath(String value) h R6Pj"@0  
{ Ry?f; s  
sFilePath = value; ~mv5{C  
} N:Ir63X*#  
 P.mlk>r  
Q^* 3 3  
public String getSFileName() O]Y   z7  
{ \l`{u)V  
return sFileName; bL+}n8B  
} ofPv?_@  
y! QYdf?  
,R-aO= %  
public void setSFileName(String value) P>03 DkbB  
{ Py?Q::  
sFileName = value; iJCv+p_f  
} jvo^I$|2h  
4U u`1gtz  
2^f7GP  
public int getNSplitter() )CgH|z:=b  
{ imKMPO=  
return nSplitter; QV4FA&f&  
} 4=N(@mS  
Yb1Q6[!  
a>Zp?*9  
public void setNSplitter(int nCount) sk AF6n  
{ {i}E)Np  
nSplitter = nCount; bfy=  
} !/=.~B  
} zJ@^Bw;A^@  
ntW1 )H'o  
Pw5[X5.DX  
/* QZ*gR#K]Sz  
**Utility.java [ugr<[6  
*/ MV07RjeS  
package NetFox; -=ZDfM  
q;7DH4;t  
}]JHY P\  
public class Utility { aM(x--UR=  
\xQu*M:!  
7:<A_OLi  
public Utility() +oL@pp0  
{ \1QY=}  
G.PRPl  
'K#ndCGJ$  
} %joL}f[  
<Y$( l szT  
//线程睡眠 )V&hS5P=S  
public static void sleep(int nSecond) 4yjIR?  
{ \k^ojzJ  
try{ 8 VhU)fY  
Thread.sleep(nSecond); g!9|1z  
} l[rK)PM   
catch(Exception e) h[Uo6`  
{ <1 ;pyw y  
e.printStackTrace (); e+MQmW A'F  
} yrd1J$  
} vTTXeS-b  
<XN=v!2;  
//日志 NCl@C$W9q  
public static void log(String sMsg) d`~~Ww1  
{ Q|e-)FS)  
System.err.println(sMsg); 90K&oof?M  
} UM<s#t`\3  
^)(tO$S  
w4M;e;8m[U  
public static void log(int sMsg) p<,`l)o}~  
{ TwI'XMO;A  
System.err.println(sMsg);  qI${7  
} JYv<QsD  
} PTqia!  
_ElG&hyp  
]hoq!:>M1  
/* k+vfZ9bD(J  
**TestMethod.java m/ID3_  
*/ k[,0kP;  
package NetFox; VqxK5  
}r!hm?e  
3dSC`K  
public class TestMethod { _uXb>V*8  
J_.cC  
b&dv("e 4  
public TestMethod() KHgn  
{ ///xx/weblogic60b2_win.exe d ez4g  
try{ P,9Pn)M|  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D /GE-lq  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); '4Fwh]Ee  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8/&4l,M5  
fileFetch.start(); >?rMMR+A  
} F=e-jKogK  
catch(Exception e){e.printStackTrace ();} v+8Ybq  
K1Uq` TJ  
L(sT/  
} /,UnT(/k(  
P.QF9%  
~QDM .5  
public static void main(String[] args) C+[)^ 2M{  
{ aB?usVoS  
new TestMethod(); aT(_c/t.  
} R n]xxa'  
} +jyGRSo  
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