http断点续传简单实现（java)

亚文隆

级别: 经院学前班

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

只看楼主更多操作楼层直达

0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 6M&ajl`o
} @2. :fK
for(int i=0;i<nEndPos.length-1;i++) R98YGW_ dT
{ Qq.$!$
nEndPos = nStartPos[i+1]; AJ>E\DK0]
} \( V1-,
nEndPos[nEndPos.length-1] = nFileLength; +`wr{kB$~
} m%u`#67oK
} kOo Vqu
TYD( 6N
`AE6s.p?
//启动子线程 !yj1X Ar
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #2i$:c~
for(int i=0;i<nStartPos.length;i++) 7.VP7;jys
{ N KgEs
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^A&{g.0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), K_Y{50#
nStartPos,nEndPos,i); +|bmUm<2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Zs/-/C|
fileSplitterFetch.start(); Dti-*LB1
} <2@t~9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0vLx={i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -w2^26ax
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", XGR63hXND
nEndPos = " + nFileLength); wuY-f4
// fileSplitterFetch[nPos.length-1].start(); 2|\mBP`ok
uq9mq"
V^FM-bg%9
//等待子线程结束 yx`@f8Kr
//int count = 0; bj0HAgY@
//是否结束while循环 d(t)8k$
boolean breakWhile = false; ::02?
W (TTsnnx
+&"W:Le:
while(!bStop) A4l"^dZc
{ [wSoZBl
write_nPos(); Mfz(%F|<
Utility.sleep(500); wH@<0lw`<
breakWhile = true; GB `n
<hy!B4
_3wJ;cn.
for(int i=0;i<nStartPos.length;i++) RgFpc*.T
{ o"RE4s\G~r
if(!fileSplitterFetch.bDownOver) o/ \o-kC}
{ Kc r)W
breakWhile = false; W'k&DKhTqF
break; 1G`5FU
} nUONI+6Z/
} .Sw4{m[g
if(breakWhile) ;w%g*S
break; `,pBOh|'
}T902RL0
w0js_P-uv
//count++; *URY8a`bO
//if(count>4) 056yhB
// siteStop(); .-s!} P"
} aAoAjVNkK
T06w`'aL
X+emJ&Z$@
System.err.println("文件下载结束！"); UlN}SddI9
} ,t1s#*j\!q
catch(Exception e){e.printStackTrace ();} /mE:2K]C
} PK?}hz
{QK9pZB
hhjsg?4uL
//获得文件长度 ]]V=\.y
public long getFileSize() ]6=opvm
{ QKz2ONV=)
int nFileLength = -1; H-5f!>)
try{ ,,9vk\
URL url = new URL(siteInfoBean.getSSiteURL()); /$vX1T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <N80MUL|
httpConnection.setRequestProperty("User-Agent","NetFox"); /e*<-a
< R@&<E6
&:+_{nc,
int responseCode=httpConnection.getResponseCode(); kgmb<4p
if(responseCode>=400) Yic'p0< ?V
{ CA"`7<,
processErrorCode(responseCode); Git2Cet
return -2; //-2 represent access is error C$c.(5/O
} yNx"Ey dk`
)>=|oY3
gY=+G6;=<
String sHeader; S 1Ji\
x2f_>tu2
qn\>(&
for(int i=1;;i++) >yqL
{ JY>I
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); D3 E!jQ1
//Utility.log(in.readLine()); i%B$p0U<
sHeader=httpConnection.getHeaderFieldKey(i); :\1&5Pm]
if(sHeader!=null) :(x 90;DW
{ 9=~jKl%\vJ
if(sHeader.equals("Content-Length")) Fn%:0j
{ ?at~il$z'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Y.Ew;\6U
break; *KV]MdS
} &l|B>{4v
} g(;ejKSR
else MN)<Tr2f
break; AB#hhi#
} tv|=`~Y
} [K9q+
catch(IOException e){e.printStackTrace ();} E3KPJ`=!*"
catch(Exception e){e.printStackTrace ();} 2W~2Hk=0+%
!8s:3]
~E`A,
Utility.log(nFileLength); )5V1HWjU
$S cjEG:6
wy&*6>.
return nFileLength; "|&*MjwN6
} MDCf(LhEH
C,z]q$4
pcl_$2_
//保存下载信息（文件指针位置） SoY&R=
private void write_nPos() {S&&X&A`v
{ yq,5M1vR
try{ ;~q)^.K3
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1!NaOfP;@
output.writeInt(nStartPos.length); "7 4L
for(int i=0;i<nStartPos.length;i++) t[ MRyi)LF
{ mLYB6
// output.writeLong(nPos); &]c9}Ic
output.writeLong(fileSplitterFetch.nStartPos); \%^3Izsc
output.writeLong(fileSplitterFetch.nEndPos); ! O>mu6:Rf
} +%~g$#tlJo
output.close(); K^vMIoh
} 5m3sjcp_
catch(IOException e){e.printStackTrace ();} y|mR'{$I
catch(Exception e){e.printStackTrace ();} 8UZEC-K
} %qv7;E2C
Zn!SHj
cK } Qu
//读取保存的下载信息（文件指针位置） t8[:}[Jx
private void read_nPos() A|+{x4s`
{ $7*Ml)H!9
try{ M;bQid@BG
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <Jk|Bmw;
int nCount = input.readInt(); }?^G=IP4(
nStartPos = new long[nCount]; 5-QXvw(TH
nEndPos = new long[nCount]; tpctz~ .
for(int i=0;i<nStartPos.length;i++) y%y#Pb|
{ 1$W!<:uh
nStartPos = input.readLong(); PrcM'Q
nEndPos = input.readLong(); _Owz%
} dd+).*
input.close(); XDGZqkt
} aU!UY(
catch(IOException e){e.printStackTrace ();} :[&X*bw[
catch(Exception e){e.printStackTrace ();} b,W'0gl
} hg~fFj3ST
{%Y7]*D
=EJ"edw]%0
private void processErrorCode(int nErrorCode) a*8}~p,
{ {mQJ6 G'ny
System.err.println("Error Code : " + nErrorCode); B+LNDnjO]
} @:@rks&
Y(f-e,
wMoAvA_oS
//停止文件下载 #rwR)9iC0
public void siteStop() F8I<4S
{ JNz0!wi
bStop = true; `dZ|}4[1
for(int i=0;i<nStartPos.length;i++) $%-?S]6)
fileSplitterFetch.splitterStop(); u|c+w)a
5PPpX=\
lUEyo.xVt
} gib]#n1!p
} M=A9ax
//负责部分文件的抓取 M)7enp) F.
**FileSplitterFetch.java ~}*;Ko\
*/ Izu.I_$4
package NetFox; \t@`]QzG:
!Xi>{nV
F{,O+\
import java.io.*; fna>>
import java.net.*; s_LSsyqo
3D0I5LF&
z sPuLn9G
public class FileSplitterFetch extends Thread { Bl];^W^P
(&,R1dLo
*lAdS]I
String sURL; //File URL 3~ZVAg[c
long nStartPos; //File Snippet Start Position w ZAXfNA
long nEndPos; //File Snippet End Position #+0R!Y
int nThreadID; //Thread's ID 5nAF=Bj
boolean bDownOver = false; //Downing is over h$\hPLx
boolean bStop = false; //Stop identical ;[ueNP%*y|
FileAccessI fileAccessI = null; //File Access interface di2=P)3
w>_EM&r6~u
5FI>T=QF
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException RfG$Px '
{ 0pa^O$?p
this.sURL = sURL; ^6>|!
this.nStartPos = nStart; g"S+V#R
this.nEndPos = nEnd; ,&]` b#Rc
nThreadID = id; NfF:[qwh
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )fc"])&8
} `r(J6,O
uTGvXKL7
#9VY[<
public void run() +lJ]-U|P
{ RLNuH2y;
while(nStartPos < nEndPos && !bStop) @(fY4]K
{ bGc|SF<V
e~]e9-L>I
yuDd% 1k
try{ .fY<"2g
URL url = new URL(sURL); AiK4t-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ':)j@O3-
httpConnection.setRequestProperty("User-Agent","NetFox"); S@NhEc
String sProperty = "bytes="+nStartPos+"-"; VQMd[/
httpConnection.setRequestProperty("RANGE",sProperty); _6zP]|VBr
Utility.log(sProperty); kTc5KHJ7
9XvM%aHs:
n4T2'e
InputStream input = httpConnection.getInputStream(); {eN{Zh5"
//logResponseHead(httpConnection); vqz#V=J{
.+L_!A
f?^Oy!1]
byte[] b = new byte[1024]; {<4?o? 1g
int nRead; '4lT*KN7\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xh^ZI6L<
{ udI:]:,P
nStartPos += fileAccessI.write(b,0,nRead); <sYw%9V
//if(nThreadID == 1) rRrW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C|IQM4
} c&?a,fpb
3nC#$L-
O8~U<'=*
Utility.log("Thread " + nThreadID + " is over!"); !2U7gVt"*
bDownOver = true; ^ R^N`V
//nPos = fileAccessI.write (b,0,nRead); `=$jc4@J
} A+1]Ql)$
catch(Exception e){e.printStackTrace ();} :F w"u4WI
} xc<eU`-'b
} Sb9=$0%\
)bXx9,VL
V&j.>Y
//打印回应的头信息 h*%0@
public void logResponseHead(HttpURLConnection con) \g:qQ*.
{ lJ]\
for(int i=1;;i++) ?"<r9S|[O
{ 0H&U=9'YT
String header=con.getHeaderFieldKey(i); vWi.[]
if(header!=null) !0csNg!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qwNKRqT
Utility.log(header+" : "+con.getHeaderField(header)); Xt,,AGm}
else <AAZ8#^
break; G<^]0`"+)t
} IL[|CB1v
} P2Qyz}!wo
)4L%zl7
2HK
public void splitterStop() ogc('HqF^'
{ !ga(L3vf
bStop = true; 4>"cc@8&~
} #u<oEDQ
'f?&EsIV?
n@07$lY@;
} ?y*+^E0
.xLF}{u
97]a-)SA
/* Il^\3T+
**FileAccess.java [#>$k 6F*
*//文件访问(定位，写) igj={==m
package NetFox; qzHqj;
import java.io.*; dp[w?AMhM9
^0s\/qyqm
3?*M{Y|
public class FileAccessI implements Serializable{ `Ge+(1x
VTJIaqw
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 aZawBU.:
RandomAccessFile oSavedFile; s7.p$r
long nPos; ^0`<k
`z?KL(rI
E/dO7I`B
public FileAccessI() throws IOException hLyTUt~\L
{ |,1bkJt
this("",0); =~\]3g
} %7NsBR!y
5U)ab3:
kh<pLI>$h
public FileAccessI(String sName,long nPos) throws IOException >St.&#c
{ 0j{F^rph
oSavedFile = new RandomAccessFile(sName,"rw"); C?w<$DU
this.nPos = nPos; Y3P.|
oSavedFile.seek(nPos); +-H}s`
} 'nlRY5@2
[:nx);\
bSrRsgKvT
public synchronized int write(byte[] b,int nStart,int nLen) ':!3jZP"m
{ a@fE46o6<
int n = -1; c?!YFm
try{ 2/v35| ?
oSavedFile.write(b,nStart,nLen); mFqSD
n = nLen; E7X!cm/2<
} poXLy/K
catch(IOException e) $N}/1R^?r
{ * MSBjH|
e.printStackTrace (); o%Be0~n'
} fJ)N:q`
> $w^%I
&jV9*
return n; ;dqk@@O"(
} uFwU-LCe
c Ndw9?Z
G3RrjWtO
} On{~St'V
DR k]{^C~
^Yj"RM$;N
/* AIZW@Nq.5
**SiteInfoBean.java gd337jw
*/ `6a]|7|f
package NetFox; I86e&"40
"sF Xl
e#>tM
public class SiteInfoBean { iD>G!\&
cPpu
nK+lE0
private String sSiteURL; //Site's URL r1i$D
private String sFilePath; //Saved File's Path <,jAk4
private String sFileName; //Saved File's Name x}tKewdOSe
private int nSplitter; //Count of Splited Downloading File CJzm}'NY
Eo%UuSi
W8f`J2^"M
public SiteInfoBean() U?bG`. X
{//nSplitter的缺省值为5 Q`H# fS~
//default value of nSplitter is 5 1#grB(p?
this("","","",5); p/r~n'g$
} CN$I:o04C
(# JMB)
'@'B>7C#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ecn}iN
{ `vudS?
sSiteURL= sURL; %$Aqbd
sFilePath = sPath; $bk>kbl P
sFileName = sName; E@:Q 'g%
this.nSplitter = nSpiltter; wD`[5~C{
Yt -W1vl
nz^nptw
} /:U1!9.y
5N\+@grp
SU/G)&Mi
public String getSSiteURL() aSUsyOe
{ }/20%fP
return sSiteURL; |VK:2p^ u
} <nBo}0O}
`%|u!
C5Xof|#p|
public void setSSiteURL(String value) pjACFVMFX
{ dgXg kB'
sSiteURL = value; :AZp}
} qmEoqU
<KtBv Ip]
TM0b-W (H
public String getSFilePath() Vn'?3Eb<
{ 6z Ay)~
return sFilePath; D3y>iQd
} o5P&JBX<
CJp-Y}fGEA
gV|Y54}T
public void setSFilePath(String value) Rs2-94$!5
{ okz]Qc>G
sFilePath = value; 5C B%=iL{
} UxeL cUP
Je^Y&a~
&3I$8v|!?
public String getSFileName() ilv_D~|
{ IP04l;p/
return sFileName; :9`qogF>
} 45)D+
&mcR
(xL :;
public void setSFileName(String value) x9%-plP
{ q[P~L`h S
sFileName = value; Y''6NGf
} d@ZoV
&$F[/[Ds+
i j/o;_
public int getNSplitter() iS
{ D"cKlp-I6|
return nSplitter; ,Aj }]h\L
} Ukc'?p,*
Q2"WV
333u]
public void setNSplitter(int nCount) r1G8]agO
{ )Oievu_"|
nSplitter = nCount; MtUY?O.P2
} ~M*gsW$
} `VZZ^K9zR
WYLX?x
(B:uc_+
/* .!yq@Q|=u
**Utility.java skR,-:"8
*/ zh%qS~8Yv
package NetFox; ~KRnr0
p+[}Hxx=
X2^_~<I{,
public class Utility { HN68!v}C|
o?wt$j-
R hio7C
public Utility() K/|
{ v9rVpYc"
S?4KC^Y5
p=B?/Sqa
} 7`fY*O6
7|Dn+=
//线程睡眠 d}-'<Z#G
public static void sleep(int nSecond) -:SIS`0s
{ TwFb%YM
try{ 2ykCtRe
Thread.sleep(nSecond); iBoEZEHjw
} jdM=SBy7q
catch(Exception e) k[9A,N^lZB
{ aZKXD! 4
e.printStackTrace (); 5UOk)rOf
} rzu s
} 4AHL3@x
C:GvP>
//日志 /{X_ .fv<v
public static void log(String sMsg) d>!p=O`>{q
{ 3cC }'j
System.err.println(sMsg); 9j#@p
} zfjw;sUX
f#P_xn&et
$Nu)E
public static void log(int sMsg) "}zda*z8
{ J]fS({(\I
System.err.println(sMsg); t5)J;0/
} 10MU-h.)
} uTGcQs}
;|TT(P:d
^~l $&~
/* wiE]z
**TestMethod.java RH1uVdJ1
*/ ]k*1KP
package NetFox; ``9 GY
7lU.Nit
*48IF33&s
public class TestMethod { };sMU6e
D$nK`r
g$3>~D
public TestMethod() G9RP^
{ ///xx/weblogic60b2_win.exe M<[?g5=#
try{ 'm O2t~n
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2jA%[L9d^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); h\y-L~2E
SiteFileFetch fileFetch = new SiteFileFetch(bean); &1GUi{I
fileFetch.start(); U8O(;+
} 3ATjsOL
catch(Exception e){e.printStackTrace ();} 6vp0*ww
5 =Z!hQ}
.wc = ]
} }.{}A(^YR
J_ J+cRwq
7&6Y
public static void main(String[] args) @2e2^8X7f
{ C5n?0I9
new TestMethod(); CBHc A'L
} ~FUa:KYD
} ^l!L)iw
点击下载更多相关资料