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
  • 11009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
/* Ve{n<{P  
**SiteFileFetch.java hd+]Ok7"  
*/ TG}d3ZU !  
package NetFox; %$@1FlqX;  
import java.io.*; j'K38@M:MN  
import java.net.*; F{<5aLaYti  
-?s&pKi  
yuOS&+,P  
public class SiteFileFetch extends Thread { kv6Cp0uFg  
>F1G!#$0  
~h-C&G ,v  
SiteInfoBean siteInfoBean = null; //文件信息Bean xwRhs!`t1  
long[] nStartPos; //开始位置 9lf*O0Z&n  
long[] nEndPos; //结束位置 6{q;1-8j+j  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 vT|`%~Be  
long nFileLength; //文件长度 HPrq1QpK  
boolean bFirst = true; //是否第一次取文件 q:I$EpKf?Q  
boolean bStop = false; //停止标志 j5Qo*p  
File tmpFile; //文件下载的临时信息 8S\RN&T$  
DataOutputStream output; //输出到文件的输出流 u*3NS$vH  
UtnZNdl v  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 07V8;A<,  
public SiteFileFetch(SiteInfoBean bean) throws IOException ,7W:fwdR  
{ {( #zcK  
siteInfoBean = bean; o*">KqU`b  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Dj i^+;"&  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); cHx%Nd\  
if(tmpFile.exists ()) JK]R*!{n  
{ h.)h@$d  
bFirst = false; *U;'OWE[  
read_nPos(); 9'?se5\  
} aSC9&Nf;  
else )p<WDiX1!e  
{ y<pnp?x4  
nStartPos = new long[bean.getNSplitter()]; c.A Yx I"  
nEndPos = new long[bean.getNSplitter()]; ~vHk&r]|  
} F.tfgW(A@  
mpgO s  
-(i(02PX  
k|xtrW`qo;  
} Y34/+Fi  
G O{ . 9_2  
*wuqa) q2  
public void run() !*aPEf270  
{ u:&o}[  
//获得文件长度 ~e `Bq>  
//分割文件 Kz jC/1sd  
//实例FileSplitterFetch c~0{s>  
//启动FileSplitterFetch线程 oc7$H>ET1  
//等待子线程返回 M*sR3SZ  
try{ TX}T|ri  
if(bFirst) \\06T `  
{ \P;rES'  
nFileLength = getFileSize(); o!OMm!  
if(nFileLength == -1) 0fm*`4Q  
{ ~ Vw9  
System.err.println("File Length is not known!"); RBwO+J53y  
} ]}Z4P-"t  
else if(nFileLength == -2) ST5V!jz  
{ Tlq-m2]  
System.err.println("File is not access!"); 'm3t|:nMU  
} X T[zj <&_  
else .B72C[' c  
{ hB9Ee@  
for(int i=0;i<nStartPos.length;i++)  x}TS  
{ p8}(kHUp(  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); QSw<%pcJE@  
} ht=P\E  
for(int i=0;i<nEndPos.length-1;i++) ! }f1`/   
{ g13 rx%-  
nEndPos = nStartPos[i+1]; mO*^1  
} #>[a{<;Kn  
nEndPos[nEndPos.length-1] = nFileLength; q5x[~]?  
} 5O <>mCF  
} |TsE-t*E}  
GOT1@.Y  
+k\Uf*wh  
//启动子线程 }|\d+V2On  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /PzcvN  
for(int i=0;i<nStartPos.length;i++) q[3x2sR  
{ i;z{zVR  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^T5X)Nu{=C  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), h6_(?|:-(  
nStartPos,nEndPos,i); C NsNZJ  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m8R9{LC  
fileSplitterFetch.start(); JL=U,Mr6  
} bWWXc[O2&(  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %FZ2xyI.  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {ZU1x C  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .zg8i_  
nEndPos = " + nFileLength); 7O5`v(<9n>  
// fileSplitterFetch[nPos.length-1].start(); 5U`ZbG  
oF]cTAqhC.  
|re}6#TgcT  
//等待子线程结束 `B/0iA  
//int count = 0; i;/xK=L  
//是否结束while循环 g.py+ ZFJ  
boolean breakWhile = false; [XVEBA4GI  
wh6yPVVF/  
Q=mI 9  
while(!bStop) oA] KE"T  
{ `x8J  
write_nPos(); xu5ia|gYz7  
Utility.sleep(500); j/`94'Y  
breakWhile = true; k%s_0 @  
<BFQ:  
&;yH@@Z  
for(int i=0;i<nStartPos.length;i++) r;BT,jiX  
{ qfY5Ww$8  
if(!fileSplitterFetch.bDownOver) o+w;PP)+=  
{ Zxr!:t7  
breakWhile = false; Fm\"{)V:b  
break; in+}/mwfC  
} x8Loyt_C  
} fmqb` %  
if(breakWhile) KWAb-yB  
break; 7ELMd{CD  
{]_uMg#!  
;~fT,7qBah  
//count++; [.se|]t7X  
//if(count>4) Od+6 -J  
// siteStop(); [x=jH>Y  
} Kl7WQg,XOi  
]i(-I <`  
8Jf.ECQT  
System.err.println("文件下载结束!"); U,#yqER'r  
} > fnh+M  
catch(Exception e){e.printStackTrace ();} x:-.+C%  
} Z4<L$i;/jN  
T|J9cgtS  
L86n}+ P\  
//获得文件长度 E)Gw0]G  
public long getFileSize() O[tvR:Nh  
{ Q!- 0xlx  
int nFileLength = -1; P-F)%T[  
try{ W} WI; cI  
URL url = new URL(siteInfoBean.getSSiteURL()); Lbe\@S   
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .2d9?p3Y  
httpConnection.setRequestProperty("User-Agent","NetFox"); :w}{$v}#D;  
T134ZXqqz  
ojYbR<jn9  
int responseCode=httpConnection.getResponseCode(); Xq'cA9v=$J  
if(responseCode>=400) )u))n#P  
{ Uc/+gz Z;  
processErrorCode(responseCode); #/PAA  
return -2; //-2 represent access is error DPi_O{W>  
} 5T sUQc  
J+rCxn?;g  
V5+SWXZ  
String sHeader; "$s~SIUB  
A-:O`RK  
5F`;yh+e  
for(int i=1;;i++) KiGp[eb  
{ ;&H4u)  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); z/i+EE  
//Utility.log(in.readLine()); 21k5I #U  
sHeader=httpConnection.getHeaderFieldKey(i); r0p w_j  
if(sHeader!=null) YK|bXSA[  
{ [MuEoWrq(}  
if(sHeader.equals("Content-Length")) t78k4?  
{ I*9e]m"  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8XbA'% o  
break; @lJzr3}WZ  
} <ZU=6Hq  
} $w"$r$K9K  
else /cc\fw1+  
break; o7IxJCL=Q  
}  hi g2  
} [+O"<Ua  
catch(IOException e){e.printStackTrace ();} .<kqJ|SVi  
catch(Exception e){e.printStackTrace ();} KNH1#30 K  
v<Bynd-  
y% :4b@<  
Utility.log(nFileLength); 2]%h$f+  
E=){K  
UH3sH t  
return nFileLength; >2#8B  
} mPq$?gdp  
wAnb Di{W  
!w&kyW?e  
//保存下载信息(文件指针位置) 2^?:&1:  
private void write_nPos() apE   
{ n3J53| %v  
try{ cwGbSW$t  
output = new DataOutputStream(new FileOutputStream(tmpFile)); NcY608C  
output.writeInt(nStartPos.length); }9nDo*A"}  
for(int i=0;i<nStartPos.length;i++) 9"g6C<  
{ c-.t>r &  
// output.writeLong(nPos); $-[CG7VgX%  
output.writeLong(fileSplitterFetch.nStartPos); '\jd#Kn'h  
output.writeLong(fileSplitterFetch.nEndPos); (b`]M`Fc  
} %YOndIS:  
output.close(); T|tOTk  
} 6e7{Iy  
catch(IOException e){e.printStackTrace ();} )7_"wD` z  
catch(Exception e){e.printStackTrace ();} GR\5WypoJ  
} fS^!ZPe1  
zt^48~ry  
~|<m,)!  
//读取保存的下载信息(文件指针位置) .*elggM  
private void read_nPos() 'M3">$N  
{ 610D% F  
try{ WxF:~{  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [s<^&WM/  
int nCount = input.readInt(); L~s3b  
nStartPos = new long[nCount]; !UFfsNiXZ  
nEndPos = new long[nCount]; Rb\6;i8R  
for(int i=0;i<nStartPos.length;i++) ZyEHzM{$  
{ 7Pa@1']  
nStartPos = input.readLong(); np~~mdmRK  
nEndPos = input.readLong(); V2N_8)s9W  
} PfkrOsV/m  
input.close(); 28 3 H  
} >0l"P"]  
catch(IOException e){e.printStackTrace ();} !ti6  
catch(Exception e){e.printStackTrace ();} id$Ul?z8  
} 02Ia2e.f  
< })'Y~i  
7 [g/TB  
private void processErrorCode(int nErrorCode) P6MRd/y |  
{ gzeQ|m2]  
System.err.println("Error Code : " + nErrorCode); hR.@b*q?R  
} L<fvKmo(fw  
ZY:[ekm%4Z  
.Lfo)?zG  
//停止文件下载 Mg^e3D1_  
public void siteStop() o=nsy]'&  
{ umdG(osR  
bStop = true; T~b>B`_  
for(int i=0;i<nStartPos.length;i++) 29reG,>  
fileSplitterFetch.splitterStop(); w |l1'   
KM`eIw>8  
&N;-J2M  
} , lJ  v  
} +*_5tWAc  
//负责部分文件的抓取 `SVmQSwO[  
**FileSplitterFetch.java l&}y/t4%  
*/ CpJ0m-7aIH  
package NetFox; uPniLx\t:  
Y[ N^p#t{  
+S=Rn,  
import java.io.*; vVE7fq3  
import java.net.*; Kt(-@\)!  
nJ" '  
oTT7M`P3h  
public class FileSplitterFetch extends Thread { _sbp6ZO_  
sdS^e`S  
not YeY7wR  
String sURL; //File URL ~,2/JDVJ5-  
long nStartPos; //File Snippet Start Position wfjnA~1h  
long nEndPos; //File Snippet End Position Dr6A ,3B  
int nThreadID; //Thread's ID bBY^+c<  
boolean bDownOver = false; //Downing is over `8FUX= Sh  
boolean bStop = false; //Stop identical /x1MPP>fu  
FileAccessI fileAccessI = null; //File Access interface ]%!u7z|\6  
?MQ.% J  
`l*;t`h  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException F-*2LMe  
{ ?ByM[E$  
this.sURL = sURL; xz:J  
this.nStartPos = nStart; O2"gj"D  
this.nEndPos = nEnd; 2./ 3 \n2  
nThreadID = id; +Y+Y6Ac[}  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r:]1 O*  
} @9&P~mo/  
Y \:0Ev  
HEGKX]  
public void run() gsn)Wv$h  
{ WAn'kA  
while(nStartPos < nEndPos && !bStop) |c`w'W?C6  
{ >,DbNmi  
(L`j0kPN  
WMj}kq)SY)  
try{ CSCN['x  
URL url = new URL(sURL); n>'Kp T9|  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7-BvFEM;  
httpConnection.setRequestProperty("User-Agent","NetFox"); RW P<B0)  
String sProperty = "bytes="+nStartPos+"-"; X_v[MW  
httpConnection.setRequestProperty("RANGE",sProperty); 0VK-g}"x  
Utility.log(sProperty); 'fL"txW  
5MSB dO  
Xb QlHfrS  
InputStream input = httpConnection.getInputStream(); FW.$5*f='  
//logResponseHead(httpConnection); EJ`T$JD  
\Y}3cE  
mZUfn%QXb(  
byte[] b = new byte[1024]; 3 LdQ]S  
int nRead; X*L;.@xA  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &  =/  
{ C XHy.&Vt  
nStartPos += fileAccessI.write(b,0,nRead); *x) 8fAr  
//if(nThreadID == 1) TW^/sx  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Lq>&d,F06)  
} z.rh]Zq  
rL5z]RY  
t5lO'Ll*Q]  
Utility.log("Thread " + nThreadID + " is over!"); b9XW9O `B  
bDownOver = true; !|<=ZF2  
//nPos = fileAccessI.write (b,0,nRead); O3CFme  
} =!Q7}z1QI  
catch(Exception e){e.printStackTrace ();} 95<EN (oUD  
} %2V-~.Ro6  
} Rml2"9"`  
 RD tU43  
Q#IG;  
//打印回应的头信息 i{I~mrm/'\  
public void logResponseHead(HttpURLConnection con) VS&TA>  
{ b^[F""!e  
for(int i=1;;i++) [2|kl l  
{ W Yc7aciJ  
String header=con.getHeaderFieldKey(i); vp(;W,ba:|  
if(header!=null) #b7$TV  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wR{'y)$  
Utility.log(header+" : "+con.getHeaderField(header)); wW"z  
else &ZTr  
break; A 8 vbQ  
} 6&bIXy  
} !a~`Bs$'jr  
i%6;  
SIKOFs  
public void splitterStop() _{|D  
{ xW[ -n  
bStop = true; |7#[ (%D!  
} o!~Jzd.=h  
1@gguRF:  
G7=p Bf  
} W0=O+0$^  
9!><<7TS  
V_Wwrhua  
/* # 6!5 2  
**FileAccess.java V#jWege  
*//文件访问(定位,写) F_bF  
package NetFox; apk4 j\i?5  
import java.io.*; ,<A$h3*  
.6OgO{P:  
a {ab*tM  
public class FileAccessI implements Serializable{ }^(}HBT  
,j5&6X=1M  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l$hJE;n  
RandomAccessFile oSavedFile; S1U@UC  
long nPos; zm,@]!wI  
"k Te2iS  
D3c2^r $Z  
public FileAccessI() throws IOException V)P&Zw  
{ "@9? QI}  
this("",0); <9sO  
} F,5r9^,_  
[TCP-bU  
MC,>pR{  
public FileAccessI(String sName,long nPos) throws IOException =YG _z^'  
{ ` gW<M  
oSavedFile = new RandomAccessFile(sName,"rw"); mm5$> [%U  
this.nPos = nPos; Uje|`<X  
oSavedFile.seek(nPos); ,/O[=9l36R  
} v2,%K`pAU  
QKE9R-K TE  
z_ =Bt  
public synchronized int write(byte[] b,int nStart,int nLen) I!wX[4p eg  
{ <58l;<0  
int n = -1; [&*6_q"V  
try{ 2m>-dqg  
oSavedFile.write(b,nStart,nLen); l6kmS  
n = nLen; ~}ET?Q7t  
} LJVG~Yeo  
catch(IOException e) A^2L~g[^Q  
{ L^^4=ao0  
e.printStackTrace (); V]S1X^  
} OMk5{-8B  
0[<~?`:)  
5b/ojr7  
return n; G4 G5PXi  
} -{ u*qtp  
N S#TW  
!Oi~:Pp  
} +PK6-c\r  
,p;_\\<  
yFhB>i  
/* e5Mln!.o  
**SiteInfoBean.java d`d0 N5\  
*/ W9oAjO NE  
package NetFox; 8^B;1`#  
%c)[ kAU!  
B cj/y4"  
public class SiteInfoBean { pG"5!42M!  
]xd^%q*  
u =gt<1U  
private String sSiteURL; //Site's URL 1b9hE9a{j  
private String sFilePath; //Saved File's Path 6bBdIqGb}  
private String sFileName; //Saved File's Name E0oU$IB  
private int nSplitter; //Count of Splited Downloading File gh6d&ucQ^  
!AJ]j|@VBd  
Npn=cLC&  
public SiteInfoBean() H.G!A6bd  
{//nSplitter的缺省值为5 KLC{7"6e)  
//default value of nSplitter is 5 TzBzEiANn  
this("","","",5); f f7(  
} V,EF'-F  
nY $tp  
iq*A("pU  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) UofTll)  
{ ^zEE6i  
sSiteURL= sURL; n-QJ;37\  
sFilePath = sPath; 0|D&"/.R#!  
sFileName = sName; V[a[i>,Z  
this.nSplitter = nSpiltter; >"3>fche  
]TstSF=  
A"Q@W<.  
} R.s|j=  
`P@- %T  
]IJv-(  
public String getSSiteURL() mDFlz1J,e  
{ Ri>?KrQF%  
return sSiteURL; `:M^8SYrL  
} 5jq=_mHt  
@6o]chJo  
djT5 X  
public void setSSiteURL(String value) d77r9  
{ -v?hqWMp#  
sSiteURL = value; 7t-Lz| $"  
} }%{MPqg  
NN 0Q`r,8}  
r+<{S\ Q  
public String getSFilePath() 5(&xNT-n8  
{ F=)eLE{W  
return sFilePath; HI&kP+,y  
} R|!B,b(  
xn}BB}s{t  
*@ED}Mj+  
public void setSFilePath(String value) GbU@BN+_  
{ ^+?|Qfi  
sFilePath = value; +pqM ^3t|y  
} pJ, @Y>  
ED} 31L  
K X]oE+:  
public String getSFileName() i[semo\E  
{ /-0' Qa+*  
return sFileName; I_ "Z:v{  
} UBO^EVJ  
U/qE4u1J6M  
]B9 ^3x[:  
public void setSFileName(String value) ?TEK=mD#u  
{ -T/W:-M(  
sFileName = value; ZI ?W5ISdg  
} 6ew "fCrH!  
2H?d+6Pt3  
%c^ m\ E  
public int getNSplitter() yZ}d+7T}  
{ +~2rW8  
return nSplitter; ,yLw$-  
} iz}sM>^  
Qu{c B^Ga*  
;)!"Ty|  
public void setNSplitter(int nCount) G5]1s  
{ 9 -jO,l  
nSplitter = nCount; KO]N%]:&~  
} w\|Ei(  
} i~qfGl p6)  
.6T6 S v  
2Eh@e([PMs  
/* SlT*C6f  
**Utility.java =;c_} VY  
*/ B!aK  
package NetFox;  YRB%:D@u  
Fm j=  
g{pQ4jKF  
public class Utility { 6*1$8G`$8,  
_py2kjA6  
0kCQ0xB[a5  
public Utility() J+<p+(^*v  
{ T%CxvZ  
[5pCL0<c@  
W7G9Kx1Y  
} nx4P^P C  
P0\eB S  
//线程睡眠 7$b?m6fmK  
public static void sleep(int nSecond) w4MwD?i]R  
{ @eQld\h'  
try{ VTh$a_P>  
Thread.sleep(nSecond); 5A_4\YpDR  
} `n-vjjG%#  
catch(Exception e) ?=|kC*$/G  
{ F>Y9o- o2  
e.printStackTrace (); /B HepD}  
} oP$kRfXS!<  
} Z}cIA87U  
k7bl'zic  
//日志 .`LgYW  
public static void log(String sMsg) @oH[SWx  
{ {tzxA_  
System.err.println(sMsg); 8@7AE"  
} q9}2  
shi Hy*(v  
dl/X."iv!  
public static void log(int sMsg) N <pbO#e  
{ k0&lu B%  
System.err.println(sMsg); F ! )-|n}  
} <lld*IH  
} =l|>.\-  
zv%J=N$G  
ZzL@[g  
/* F2oJ]th.3  
**TestMethod.java <%,'$^'DS  
*/ X!0kK8v  
package NetFox; VJ1*|r,  
/e5\9  
anx&Xj|=.F  
public class TestMethod { Q#rt<S1zW  
IrO +5w  
M]ap:  
public TestMethod() u:4["ViC  
{ ///xx/weblogic60b2_win.exe tyXl}$)y  
try{ #Go(tS~o  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); t.z$j  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); T7GQ^WnA  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;nf&c;D  
fileFetch.start(); Iu6W=A  
} R@ QQNYU.D  
catch(Exception e){e.printStackTrace ();} rdI]\UH  
)<LI%dQ:'l  
+2O=s<fp  
} MuSaK %  
Es:6  
u`p_.n:5)  
public static void main(String[] args) 1jOKcm'#  
{ Qk7J[4  
new TestMethod(); v!!;js^  
} "8t\MKt(  
} J8h7e}n?  
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