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
  • 8172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
/* 3;MjO*-  
**SiteFileFetch.java P%sO(_PuT  
*/ ^ Wfgwmh  
package NetFox; ]A72) 1  
import java.io.*; ^qO=~U!{  
import java.net.*; 8A^jD(|  
/;&+ < }  
8a`+h#  
public class SiteFileFetch extends Thread { !I5~))E  
\c~{o+UD-  
knOn UU  
SiteInfoBean siteInfoBean = null; //文件信息Bean rN1U.FRe/  
long[] nStartPos; //开始位置 - SS r  
long[] nEndPos; //结束位置 HCG@#W<wc  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 B>Cs&}Y!  
long nFileLength; //文件长度 xs'kO=  
boolean bFirst = true; //是否第一次取文件 $tCcjBK\  
boolean bStop = false; //停止标志 {^2W>^  
File tmpFile; //文件下载的临时信息 #)0Tt>d6  
DataOutputStream output; //输出到文件的输出流 y168K[p  
-, Q$  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) b"nG-0JR  
public SiteFileFetch(SiteInfoBean bean) throws IOException 0<@KDlF  
{ hyb +#R  
siteInfoBean = bean; Q"|kW[Sg  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); $iqi:vY  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); %gu$_S  
if(tmpFile.exists ()) L; q)8Pb  
{ p x|>v8  
bFirst = false; *el(+ib%  
read_nPos(); yYToiW *  
} n<?SZ^X{,/  
else T+WZE  
{ 5BHOHw D{  
nStartPos = new long[bean.getNSplitter()]; dGsS<@G  
nEndPos = new long[bean.getNSplitter()]; 3G%wZ,)C  
} |'c4er/;#  
V+O0k: o  
G7Z vfLR{:  
I{42'9  
} LiZdRr  
kxm:g)`=[  
1GG>.RCP  
public void run() ^r>f2 x  
{ }2ql?K  
//获得文件长度 m\/,cc@,  
//分割文件 `u#;MUg  
//实例FileSplitterFetch 9$o<  
//启动FileSplitterFetch线程 EK?@Z.q+  
//等待子线程返回 G; C8Kde  
try{ {jOzap|  
if(bFirst) T+;H#&  
{ )C>}"#J>  
nFileLength = getFileSize(); ZU-4})7uSB  
if(nFileLength == -1) 3J'73)y  
{ LAv:+o(m/  
System.err.println("File Length is not known!"); "Su b4F`  
} jVad)2D  
else if(nFileLength == -2) *%X6F~h(u  
{ v Zb|!#I  
System.err.println("File is not access!"); -c+>j  
} >-5td=:Z  
else .!yWF?T8  
{ X-kXg)!Bg  
for(int i=0;i<nStartPos.length;i++) ]6{(Hjt  
{ qGnPnQc  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); By?nd)  
} 7~wFU*P1  
for(int i=0;i<nEndPos.length-1;i++) P>*Fj4 Z~  
{ R2}kz.  
nEndPos = nStartPos[i+1]; /!=U +X  
} }_{y|NW  
nEndPos[nEndPos.length-1] = nFileLength; 5/B#)gm  
} D:wnO|:  
} onnI !  
t_jyyHxoZ:  
N[qA2+e$Z  
//启动子线程 vG]GQ#  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; x37/cu  
for(int i=0;i<nStartPos.length;i++) s0cs'Rg  
{ nJFk4v4:2  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .E+OmJwD  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |7 &|>  
nStartPos,nEndPos,i); u64 @"P  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #^|| ]g/N  
fileSplitterFetch.start(); (n=9c%w  
} !1a}| !Zn  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -$+,]t^GV  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); j4;Du>obQ  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", i@P 9EU  
nEndPos = " + nFileLength); <7=&DpjI7F  
// fileSplitterFetch[nPos.length-1].start(); TC qkm^xv  
O( VxMO  
}@Xh xZu  
//等待子线程结束 +J|+es  
//int count = 0; i[$-_  
//是否结束while循环 ]SFWt/<  
boolean breakWhile = false; pw@`}cM=  
]\A1mw-T  
w#*/y?"D  
while(!bStop) m8'@UzB  
{ `-VG ?J  
write_nPos(); w6vLNX  
Utility.sleep(500);  fO K|:  
breakWhile = true; sffhPX\I  
-i#J[>=w{C  
-Q6(+(7_|  
for(int i=0;i<nStartPos.length;i++) 9Ei5z6Vk/+  
{ N99[.mErU  
if(!fileSplitterFetch.bDownOver) ^_@r.y]  
{ :<L5sp  
breakWhile = false; /@VsqD  
break; {'NBp0i  
} ^^%JoQ.  
} /K7Bae5h  
if(breakWhile) v@VLVf)>9^  
break; HLVQ7  
& x`&03X  
Qh*)pt]n  
//count++; <mL%P`Jj  
//if(count>4) `M&P[ .9Pz  
// siteStop(); 5J  ySFG3  
} j(j#0dXLh  
[w!C*_V 9  
G\R*#4cF  
System.err.println("文件下载结束!"); ^w.]Hd 2  
} w&%9IJ  
catch(Exception e){e.printStackTrace ();} 6Lb{r4^  
} Hb+X}7c$  
>Iuzk1'S  
{@3z\wMK$  
//获得文件长度 u$C\E<G^  
public long getFileSize() :$Q`>k7A  
{ 1Pm4.C)  
int nFileLength = -1; V\0E=M*P  
try{ jgG$'|s}  
URL url = new URL(siteInfoBean.getSSiteURL()); u^t$ cLIZ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /hL\,x 2  
httpConnection.setRequestProperty("User-Agent","NetFox"); g0PT8]8  
E, GN|l  
Qlw>+y-i  
int responseCode=httpConnection.getResponseCode(); ["u#{>(X  
if(responseCode>=400) 58::h. :  
{ OZf6/10O/  
processErrorCode(responseCode); Zae.MO^C!  
return -2; //-2 represent access is error k0JW[04j  
} S<"oUdkz  
%)?`{O~ h  
zVw:7-  
String sHeader; Or7 mD  
EkjgNEXq  
V43TO  
for(int i=1;;i++) RND9D\7  
{ V^WU8x  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Fk{J@Y  
//Utility.log(in.readLine()); {=67XrWN1  
sHeader=httpConnection.getHeaderFieldKey(i); 8f|98T"  
if(sHeader!=null) j C)-`_  
{ l-<`m#/v  
if(sHeader.equals("Content-Length")) Sm)u9  
{ V7EQ4Om:It  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); TN\|fzj  
break; R:M,tL-l  
} V,Q4n%h1.  
} nBkh:5E5%  
else O#)jr-vXdV  
break; 49AW6H.JT  
} ^XG*z?Tt  
} `<U5z$^QTw  
catch(IOException e){e.printStackTrace ();} #Y2i*:<  
catch(Exception e){e.printStackTrace ();} f"dSr  
2Q@Y^t   
YHB9mZi  
Utility.log(nFileLength); RO.U(T  
D<>@ %"%  
zU&L.+   
return nFileLength; .XS9,/S  
} ?2 f_aY ;  
Z+4D.bA  
dEp7{jY1O  
//保存下载信息(文件指针位置) eM2|c3/  
private void write_nPos() du_4eB  
{ /&^W#U$4  
try{  U>a\j2I  
output = new DataOutputStream(new FileOutputStream(tmpFile)); cE\>f8 I  
output.writeInt(nStartPos.length); 36vgX=}  
for(int i=0;i<nStartPos.length;i++) @kxel`,$e  
{ Dd,2;#_  
// output.writeLong(nPos); r@kP*  
output.writeLong(fileSplitterFetch.nStartPos); QI_4*  
output.writeLong(fileSplitterFetch.nEndPos); A&"%os  
} M'L;N!1A  
output.close(); &%mXYj3y5  
} xfFg,9w8  
catch(IOException e){e.printStackTrace ();} }t%W1UJ  
catch(Exception e){e.printStackTrace ();} (Un_!)  
} NxA)@9Q  
]uQqn]+I!  
2=iH$v  
//读取保存的下载信息(文件指针位置) ] )}]/Qw  
private void read_nPos() ?LK 2g  
{ IzLQhDJ1  
try{ S DLvi!y  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t#i,1aHA  
int nCount = input.readInt(); n, i'Dhzk  
nStartPos = new long[nCount]; )"+2Z^1-  
nEndPos = new long[nCount]; T~:|!`  
for(int i=0;i<nStartPos.length;i++) ep/Y^&$M  
{ 0#cy=*E  
nStartPos = input.readLong(); ]#2Y e7+  
nEndPos = input.readLong(); /Q{P3:k  
} .iD*>M:W  
input.close(); OEx^3z^  
} Z\}K{#   
catch(IOException e){e.printStackTrace ();} C3NdE_E  
catch(Exception e){e.printStackTrace ();} wU\s; dK  
} fw6UhG  
sarq`%zrk  
U.!lTLjfLz  
private void processErrorCode(int nErrorCode) 7R!5,Js+  
{ j hbonuV_  
System.err.println("Error Code : " + nErrorCode); e]=lKxFh&l  
} ::FS/Y]Fg  
B=8Iu5m  
uvP2Wgt  
//停止文件下载 #n0Y6Pr  
public void siteStop() 5NoI~X=  
{ V-'K6mn;  
bStop = true; o]:3H8  
for(int i=0;i<nStartPos.length;i++) r$Co0!.  
fileSplitterFetch.splitterStop(); ';Zi@f"  
\.YS%"Vz  
1$qh`<\  
} a<}#HfC;'  
} o*U]v   
//负责部分文件的抓取 )q7UxzE+  
**FileSplitterFetch.java )XcOl7XLN  
*/ e@:sR  
package NetFox; {:@tQdM:i8  
^WBuMCe  
;qHOOT  
import java.io.*; >D201&*G%  
import java.net.*; E dZ\1'&/9  
pvmC$n^zc  
cuy1DDl  
public class FileSplitterFetch extends Thread { S26MDLk`R3  
Vz6Qxd{m3  
Reatd h  
String sURL; //File URL Jgnhn>dHe  
long nStartPos; //File Snippet Start Position da)NK!  
long nEndPos; //File Snippet End Position 6G=j6gK%P  
int nThreadID; //Thread's ID M1KqY:9E  
boolean bDownOver = false; //Downing is over -D6exTxh"  
boolean bStop = false; //Stop identical vWGwVH/K  
FileAccessI fileAccessI = null; //File Access interface r@ZJ{4\Q  
kbM3  
5mb]Q)f9-  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException EkziAON  
{ jH_JmYd  
this.sURL = sURL; BcI |:qv|  
this.nStartPos = nStart; zOQ>d|p?X  
this.nEndPos = nEnd; B^g ?=|{  
nThreadID = id; q$=#A7H>3)  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (<^yqH?  
} w*R$o  
8By|@LO  
eq U ME  
public void run() h: 9Zt0,  
{ #8)*1?  
while(nStartPos < nEndPos && !bStop) 6Fe34n]m  
{ `r?7oxN  
K4kMM*D  
I_RsYw  
try{ qgfi\/$6  
URL url = new URL(sURL); o"*AtGR+"  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YpqrZWvh  
httpConnection.setRequestProperty("User-Agent","NetFox"); =ZqT3_  
String sProperty = "bytes="+nStartPos+"-"; G;YrF)\  
httpConnection.setRequestProperty("RANGE",sProperty); r?/'!!4  
Utility.log(sProperty); Fi0GknQ+  
EAM5{Nc  
~c\e'&sc;  
InputStream input = httpConnection.getInputStream(); RsYU59_Y  
//logResponseHead(httpConnection); t<#h$}=:Vt  
b9!FC$^J  
WYr/oRO  
byte[] b = new byte[1024]; BqT y~{)+  
int nRead; *c2YRbU(  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) lv04g} W  
{ soQ1X@"0  
nStartPos += fileAccessI.write(b,0,nRead); >rf'-X4n  
//if(nThreadID == 1) |j,"Pl}il^  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =uS9JU^E  
} ;n 7/O5M|  
>Z5gSs0  
:\|SQKD  
Utility.log("Thread " + nThreadID + " is over!"); 9E6_]8rl  
bDownOver = true; `E>1>'  
//nPos = fileAccessI.write (b,0,nRead); [EKQR>s)  
} "yS _s  
catch(Exception e){e.printStackTrace ();} P}4QQw  
} .4E&/w+  
} .nVa[B |.  
BBev<  
T \_ ]^]>  
//打印回应的头信息 9?SZNL['V  
public void logResponseHead(HttpURLConnection con) U[ 0=L`0e  
{ va0{>Dc+  
for(int i=1;;i++) jEZMUqGY!  
{ Rd#WMo2Xd  
String header=con.getHeaderFieldKey(i); ojan Bg   
if(header!=null) Ys\Wj%6A  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); H*r)Z 90  
Utility.log(header+" : "+con.getHeaderField(header)); 4GX-ma,  
else  B\o Mn  
break; C)`Fv=]R  
} 85LAY aw  
}  z62;cv  
j3{D^|0bP  
eLfk\kk]Pc  
public void splitterStop() XMxSQ B1  
{ H<PtAYFS  
bStop = true; tg<EY!WY  
} q-}Fvel u  
3v1iy / /  
UdpF@Q  
} <4HDZ{"M  
gMzcTmbc8  
zdYy^8V|z  
/* =\H!GT  
**FileAccess.java d^{RQ   
*//文件访问(定位,写) |Uc_G13Y{D  
package NetFox; ~Vr.J}]J  
import java.io.*; ;)D];u|_  
Utnr5^].2O  
^c9t'V`IWQ  
public class FileAccessI implements Serializable{ CEX " D`  
t.xxSU5~%  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 AP'*Nh@Ik(  
RandomAccessFile oSavedFile; I|^;B 8[  
long nPos; {y=j?lD  
K/IWH[  
wk5s)%V  
public FileAccessI() throws IOException Ab{ K<:l  
{ W04@!_) <  
this("",0); ahJ`$U4n  
} n>BkTaI  
Uq^#riq  
zh8nc%X{  
public FileAccessI(String sName,long nPos) throws IOException Vex{.Vh,"  
{ Cv6'`",Yzm  
oSavedFile = new RandomAccessFile(sName,"rw"); ;DFSzbF`  
this.nPos = nPos; 21K>`d\  
oSavedFile.seek(nPos); )48QBz?  
} ;:\<gVi:  
<G|(|E1  
_`&m\Qe>  
public synchronized int write(byte[] b,int nStart,int nLen) 1v.c 6~  
{ Rwz0poG`WG  
int n = -1; *U&0<{|T  
try{ :~Wrf8 UQ  
oSavedFile.write(b,nStart,nLen); L^@'q6*}  
n = nLen; J}v}~Cv  
} \LR~r%(rM  
catch(IOException e) 4T|b Cs?e  
{ kmP]SO?tx  
e.printStackTrace (); >=:&D)m"  
} ILEz;D{]   
2$+bJJM  
WW4vn|0v  
return n; v%+:/m1  
} hT`J1nNt  
O}-jCW;K  
6jE |  
} &Sw%<N*r  
u0|8Tgf  
}B\a<0L/  
/* )dbB =OZ  
**SiteInfoBean.java RJ  8+h  
*/ f$e[u E r  
package NetFox; 7puFz4+f  
Dfg2`l  
X[]m _@v  
public class SiteInfoBean { 6Ypc`  
Ql/cN%^j$  
v$7QIl_/7  
private String sSiteURL; //Site's URL ,?8qpEG~#+  
private String sFilePath; //Saved File's Path ORe(]I`Z  
private String sFileName; //Saved File's Name /uPcXq:L~  
private int nSplitter; //Count of Splited Downloading File ?Y-%'J(  
y{ibO}s  
^1iSn)&  
public SiteInfoBean() JEXy%hl  
{//nSplitter的缺省值为5 l=S35og  
//default value of nSplitter is 5 q rJ`1  
this("","","",5); n.'8A(,r3  
} O#:$^#j&  
\F1_lq;K  
C'\- @/  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k1w_[w [  
{ UQ)W%Y;[0  
sSiteURL= sURL; 4|buk]9  
sFilePath = sPath; >7lx=T x  
sFileName = sName; 60P#,o@G  
this.nSplitter = nSpiltter; `q}I"iS  
zMbN;tu  
i UCXAWP  
} D!{Y$;  
Xe6w|  
~ {E'@MU  
public String getSSiteURL() wvO|UP H\  
{ ML w7}[  
return sSiteURL; l~c@^!  
} sGy eb5c  
bLlKe50  
~ELNyI11  
public void setSSiteURL(String value) 2`7==?  
{ GPkmf%FJ  
sSiteURL = value; PDJr<E?  
} H$=e -L`@  
zKw`Md  
.a O,8M  
public String getSFilePath() !\zWF  
{ ?5C!<3gM)  
return sFilePath; LPZF)@|`  
} V=R 3)GC  
P\yDa*m  
+o\:d1y  
public void setSFilePath(String value) ah+~y,Gl  
{ C7rNV0.Fq  
sFilePath = value; E@@5BEB ~  
} ]$ L|  
'8Q]C*Z  
+c(zo4nZ  
public String getSFileName() rM`X?>iT+  
{ iq8Grd L"  
return sFileName; rSZd!OQ  
} 'FqQzx"r  
3.|S  
.<jr0,i  
public void setSFileName(String value) YPU*@l>  
{ }#L^!\V }  
sFileName = value; *@Lp`thq  
} iP =V8g?L  
d74d/l1*{  
8$")%_1]  
public int getNSplitter() 9!6f-K  
{ j/R[<47  
return nSplitter; zz+$=(T:M  
} KC/=TSSXd.  
(\\eo  
r[2ILe  
public void setNSplitter(int nCount) }Ga\wV  
{ ?3nR  
nSplitter = nCount; CnpV:>V=  
} -8; 7Sp1  
} bSiYHRH.e  
#r#1JtT  
 O{QA  
/* d;zai]]  
**Utility.java `P@T$bC  
*/ G/b^|;41  
package NetFox; wG~`[>y (  
3vuivU.3  
"3Uv]F  
public class Utility { LCZ\4g05  
&|Bc7+/P  
_y),J'W^3u  
public Utility() tz5e"+Tz  
{ W=j[V Oq  
Cbg!:Cws  
CLRiJ*U  
} ZIf  
5* j?E  
//线程睡眠 wLi4G@jJ  
public static void sleep(int nSecond) 3jGWkby0  
{ Y'1S`.  
try{ gbI^2=YT'  
Thread.sleep(nSecond); mkYqpD7  
} Sm)Ha:[4  
catch(Exception e) hWM< 0=  
{ mtJ9nC  
e.printStackTrace (); x}_]A$nV  
} z>XrU>}  
} =T -&j60  
xAK6pDp  
//日志 lt ^GvWg  
public static void log(String sMsg) FoNSM$x  
{ 2/?`J  
System.err.println(sMsg); mR&H9 NG  
} c#|raXGT  
nH`Q#ZFz]?  
{t0) q  
public static void log(int sMsg) =7w\ 7-.m  
{ 9Xj7~,  
System.err.println(sMsg); 19HM])Zw\  
} f({Ei`|  
} {{B%f.   
ix([mQg  
q#T/  
/* 01}C^iD  
**TestMethod.java Q~OxH'>>(  
*/ qCljo5Tq'  
package NetFox; U@HK+C"M|  
G`n_YH084  
v:!Z=I}>  
public class TestMethod { A;*d}Xe&J  
S#MZV@nGF  
GO__$%~  
public TestMethod() ]!I7Y.w6  
{ ///xx/weblogic60b2_win.exe $* AYcy7  
try{ o$#G0}yn  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2>cGH7EBD  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qHuZcht  
SiteFileFetch fileFetch = new SiteFileFetch(bean); v-#Q7T  
fileFetch.start(); SSPHhAeH8  
} rf?qdd(~cH  
catch(Exception e){e.printStackTrace ();} .$qnZWcgG  
<R''oEf9  
F$ #U5}Q  
} 1`(tf6op  
vd [}Gd  
]~aF2LJ_q  
public static void main(String[] args) 8vMG5#U[  
{ -*$HddD  
new TestMethod(); L\@I*QP  
} UJM1VAJ0  
} V8rx#H~  
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:
3+5=?,请输入中文答案:八 正确答案:八