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)); OTbjZ(
} {d5ur@G1
for(int i=0;i<nEndPos.length-1;i++) G7#~=W 2M
{ xn#I7]]G
nEndPos = nStartPos[i+1]; -)c"cgx.
} x[<#mt
nEndPos[nEndPos.length-1] = nFileLength; ^.aEKr
} Ib<+m%Ac
} <UHf7:0V
kT3;%D^
uTFEI.N
//启动子线程 vVRCM
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1 jd=R7
for(int i=0;i<nStartPos.length;i++) 9U%}"uE
{ ;R>42 qYF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |zegnq~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !)1Zp*
nStartPos,nEndPos,i); rs)aEmvC
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xH.q
fileSplitterFetch.start(); krT!AfeV
} {.[,ee-)9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v}t:}M<;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "h|0]y^2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", D+nj[8y
nEndPos = " + nFileLength); @G&xq"Fg7
// fileSplitterFetch[nPos.length-1].start(); U\plt%2m>
s.Ic3ITd,
15yV4wHr
//等待子线程结束 "pJEzC
//int count = 0; ))-M+CA
//是否结束while循环 U0=zuRr n
boolean breakWhile = false; 246!\zf
/-9+(
"PP0PL^5F
while(!bStop) hndRgCo
{ k:yu2dQh
write_nPos(); S~`AnX3!
Utility.sleep(500); mAERZ<I
breakWhile = true; T[II;[EiE
~ZIRCTQ"
P_Ja?)GT
for(int i=0;i<nStartPos.length;i++) zb*4Nsda:
{ FO3*[O
if(!fileSplitterFetch.bDownOver) icbYfgQ
{ |Y8o+O_`
breakWhile = false; +m},c-,=$w
break; |I<-x)joIK
} 0p2O8>w^%
} 4B,A+{3yL
if(breakWhile) / =<ul-K
break; #GJh:#tt^
QiL
_^A NJ7
//count++; _Pm}]Y:_
//if(count>4) F#R\Ot,hv
// siteStop(); K8we*
} Z9EQ|WfS#-
_ o3}Ly}
a#j^gu$m
System.err.println("文件下载结束！"); xJ.!Q)[
} q/G5aO*
catch(Exception e){e.printStackTrace ();} TniKH(w/
} `cRB!w=KHV
U6 R4UK
*XR~fs?/*W
//获得文件长度 y`dzo`f
public long getFileSize() (NlEb'~+
{ [Y~s
int nFileLength = -1; Z*B(L@H
try{ (KU@hp-\
URL url = new URL(siteInfoBean.getSSiteURL()); 0u9h2/ma
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ''YjeX
httpConnection.setRequestProperty("User-Agent","NetFox"); (!=aRC.-
_YUF /B'
Q*(C)/QW
int responseCode=httpConnection.getResponseCode(); +5\\wGo<
if(responseCode>=400) ,_-*/- 7;8
{ d8I:F9
processErrorCode(responseCode); bME3" e{O
return -2; //-2 represent access is error w#b2iE+Bw
} }e@-[RJ!
`v er "s;
9D21e(7X
String sHeader; EF~PM
pdu
{<n)zLy
for(int i=1;;i++) N/=3Bs0y-
{ Z}f_\d'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S!cXc/H-R
//Utility.log(in.readLine()); 1i2O]e!
sHeader=httpConnection.getHeaderFieldKey(i); p$<qT^]&
if(sHeader!=null) a06q-3zw
{ }A^,y
if(sHeader.equals("Content-Length")) P ie!Su`
{ |0mI3r
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h!]A(T\J
break; K@hUif|([
} 'kK%sE
} oPBjsQ
else `7ZJB$7D|*
break; '& :"/4@)
} _\[G7
} ,oil}N(
catch(IOException e){e.printStackTrace ();} /L^dHI]Q
catch(Exception e){e.printStackTrace ();} 2N]s}/l
8m0sEV>
xx8na8
Utility.log(nFileLength); V|`|CVFo]
YJ$ =`lIM
kRPg^Fw"Vw
return nFileLength; 0rUf'S ?K
} @9a=D<'>
mws.)
A@r,A?(
//保存下载信息（文件指针位置） G.T1rUh=
private void write_nPos() !HYqM(|{.
{ xcA:Q`c.{
try{ 4N&}hOM'S
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2D"/k'iA
output.writeInt(nStartPos.length); 470Pig>I8
for(int i=0;i<nStartPos.length;i++) m6D4J=59
{ sn%fE
// output.writeLong(nPos); kF .b)
output.writeLong(fileSplitterFetch.nStartPos); dPId= w)
output.writeLong(fileSplitterFetch.nEndPos); |zKcL3*
} 5$X{{j2
output.close(); %#~Wk|8} Q
} ,~#hHhR_
catch(IOException e){e.printStackTrace ();} J)o%83//
catch(Exception e){e.printStackTrace ();} sP%.o7&n
} >rubMGb
0M?}S~p]
><~hOK?v
//读取保存的下载信息（文件指针位置） CS49M
private void read_nPos() yk/XfwQ5
{ \\JXY*DA:+
try{ +L6d$+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?a@l.ZM*
int nCount = input.readInt(); v},sWjv
nStartPos = new long[nCount]; ZtDpCl_
nEndPos = new long[nCount]; \ :.p8`
for(int i=0;i<nStartPos.length;i++) h>?OWI
{ kTV D4Z=
nStartPos = input.readLong(); Tx_LH"8
nEndPos = input.readLong(); 7Z_iQ1
} )SuJK.IF
input.close(); 0P42C{>'w
} 5]E5V@C
catch(IOException e){e.printStackTrace ();} ?$Pj[O^hl
catch(Exception e){e.printStackTrace ();} ~m7+^c@,
} |a+8-@-Tj
26A#X
ZUycJ-[
private void processErrorCode(int nErrorCode) OgX."pK
{ G)Y!aX
System.err.println("Error Code : " + nErrorCode); _[W=1bGJ
} U' Cp3>
DNPK1e3a{
x& S>Mr
//停止文件下载 {$^|^n5j
public void siteStop() _17"T0
{ mD!imq%=
bStop = true; _ sd?l
for(int i=0;i<nStartPos.length;i++) gK /K Z8
fileSplitterFetch.splitterStop(); 4)_ [)MZ\j
e]QkZg2?Yn
#~b9H05D
} -84Z8?_
} aO1cd_d6x_
//负责部分文件的抓取 gE1".qC
**FileSplitterFetch.java ryN-d%t?
*/ |dK-r
package NetFox; PLD!BD
)8;'fE[p}
bHCd|4e,2
import java.io.*; Vq\6c
import java.net.*; (c"!0v
IF=rD-x
TR|; /yJ
public class FileSplitterFetch extends Thread { l-&f81W
dU,/!|.K
\iFE,z
String sURL; //File URL (ZYOm
long nStartPos; //File Snippet Start Position <qBPN{'a"
long nEndPos; //File Snippet End Position dZ*o H#B
int nThreadID; //Thread's ID LBg#KQ@
boolean bDownOver = false; //Downing is over )lbF'.i
boolean bStop = false; //Stop identical V47Fp
FileAccessI fileAccessI = null; //File Access interface @azS)4L
WKG=d]5
1na[=Q2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException E] [DVY
{ bpkn[K"(
this.sURL = sURL; ^P[*yf
this.nStartPos = nStart; UxW~yk
this.nEndPos = nEnd; bWqGypq4
nThreadID = id; QO8/?^d
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [7bY(
} +=R:n^r^,
?NL2|8
\vI_%su1N
public void run() XP'KgTF
{ ]n+:lsiV
while(nStartPos < nEndPos && !bStop) HN:{rAIfc
{ }~7>S5
|^ qW
8]O|$8'"
try{ <^=k~7m
URL url = new URL(sURL); 7cC$)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /<mc~S7
httpConnection.setRequestProperty("User-Agent","NetFox"); C oaqi`v4T
String sProperty = "bytes="+nStartPos+"-"; *q^'%'
httpConnection.setRequestProperty("RANGE",sProperty); !MbRI
Utility.log(sProperty); $z<CkMP!U7
_?{2{^v
&rn,[w_F[
InputStream input = httpConnection.getInputStream(); F?UL0Q|uv
//logResponseHead(httpConnection); \1tce`+
nP}/#Wy
IflpM]
byte[] b = new byte[1024]; /fX]Yu
int nRead; $1axZ~8sS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) HwDb &pP"
{ l6i 2!&8P%
nStartPos += fileAccessI.write(b,0,nRead); )T>a|.
//if(nThreadID == 1) 3}"VUS0wh
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <Sz9: hg-
} h.67]U7m
4EOu)#
c6e?)(V>
Utility.log("Thread " + nThreadID + " is over!"); _%t w#cM
bDownOver = true; U<*dDE~z
//nPos = fileAccessI.write (b,0,nRead); *@O;IiSE
} 0Vg8o @
catch(Exception e){e.printStackTrace ();} $lO\eQGxB
} =%a.C(0&G
} }%VHBkuc
1Ao"DxZHy7
"MyYu}AD
//打印回应的头信息 o:?IT/>
public void logResponseHead(HttpURLConnection con) 7QQnvoP
{ R8ZW1
for(int i=1;;i++) qWWy}5SOm
{ o}[wu:>yk
String header=con.getHeaderFieldKey(i); 1f}Dza9
if(header!=null) a1?Y7(alPU
//responseHeaders.put(header,httpConnection.getHeaderField(header)); y_\d[
Utility.log(header+" : "+con.getHeaderField(header)); *QrTZ$\C
else Ngg (<ZN
break; Cu0/TeEM
} *{XbC\j
} A>X#[qx
EB)0 iQ
p}C3<[Nk
public void splitterStop() RlpW)\{j?
{ `/0FXb 8h
bStop = true; tf>?;
} ](%-5G1<
r1,RloyZS
,#s}nJ4
} 9D&ocV3QV
grv 3aa@
ll6~8PN
/* (Y-7B
**FileAccess.java k+_pj k
*//文件访问(定位，写) uHy^ Bq
package NetFox; !W8$-iq
import java.io.*; dD#A.C,Rz
3Y>!e#
42Z2Mjtk
public class FileAccessI implements Serializable{ K !`tEW[
:[,n`0lH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :c c#e&BO
RandomAccessFile oSavedFile; <x,$ODso
long nPos; {"O'kx
[7$.)}Q-
'#^ONnSTn
public FileAccessI() throws IOException ~]}7|VN.}
{ PE3l2kr
this("",0); mhh8<BI
} T'FRnC^~
iQ:]1H s
f\1)BZ'I
public FileAccessI(String sName,long nPos) throws IOException nd-y`@z
{ %|4Nmf$:Og
oSavedFile = new RandomAccessFile(sName,"rw"); ?FD^S~bz-
this.nPos = nPos; ]Rz]"JZ\S
oSavedFile.seek(nPos); $dq R]'
} e3&R3{
{5:y,=Y
Qb/qUUQO;0
public synchronized int write(byte[] b,int nStart,int nLen) FhW\23OC
{ 5v8_ji#l[
int n = -1; 4h?[NOA"
try{ 9=Y-w s
oSavedFile.write(b,nStart,nLen); EZao\,t
n = nLen; .#P'NF(5#
} `5Q0U%`W
catch(IOException e) W$ M4#
{ UP^{'eh
e.printStackTrace (); Wcw$ Zv
} /qEoiL###
.XTBy/(0
?~hC.5
return n; JuS#p5E #
} u1(`^^Ml
)y_MI r
zJOL\J'
} f8!*4Bw
b<NI6z8\
3`$-
/* K'Wg_ihA
**SiteInfoBean.java p8frSrcU
*/ ]^p6dbzWe
package NetFox; &+Xj%x.]
_|`S9Nms
,)|nxX
public class SiteInfoBean { {IJ,y27
rOEk%kJ
.sgP3Ah
private String sSiteURL; //Site's URL .e~17}Ka}
private String sFilePath; //Saved File's Path `~F=
private String sFileName; //Saved File's Name *{/BPc0*
private int nSplitter; //Count of Splited Downloading File txw:m*(%
4DaLmQ2O
'WUd7
public SiteInfoBean() Q!iM7C!8
{//nSplitter的缺省值为5 iG^o@*}a
//default value of nSplitter is 5 1!~=8FTv
this("","","",5); @))PpE`co8
} qlNK }
2r]80sWY
B;@7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fczId"
{ |gg6|,Bt4
sSiteURL= sURL; tI~.3+F
sFilePath = sPath; =`Pgo5A
sFileName = sName; sEm-Td+A5
this.nSplitter = nSpiltter; mfc\w'
pa*bqPi
3dTz$s/[
} 8m\*~IX=
fucG 9B
Q30AaG}f
public String getSSiteURL() ~7IXJeon
{ "AMbU68
return sSiteURL; | U)
} 3A!`U6C(
YzNSZJPD
$F"'=+0
public void setSSiteURL(String value) Qyx%:PE
{ =dSH8C"
sSiteURL = value; s]@()?.E$
} T{<riJ`O
Zn0e#n
F !g>fIg
public String getSFilePath() o'O;69D]tX
{ 7&;M"?m&
return sFilePath; Wa7-N4
} DybuLB$f
+}[M&D
sxkWg>
public void setSFilePath(String value) Au~l O
{ &c>%E%!"
sFilePath = value; p8,Rr{
} w+($=n~
0N>NX?r
0h=NbLr|S-
public String getSFileName() iq*]CF
{ "NWILZwEV
return sFileName; d5jZ?
} *oZ]k`-!8
(dmLEt
?gD^K,A Hd
public void setSFileName(String value) c_wvuKa
{ o{MF'B#
sFileName = value; 4@19_+3
} i;B &~
Sy()r 6n
!1(*D*31
public int getNSplitter() L8R{W0Zr>!
{ ?TTtGbvU
return nSplitter; m#w1?y)Z@X
} b?i5C4=K
f3PDLQA
Bl[4[N
public void setNSplitter(int nCount) /5M0[C E
{ %]G'u
nSplitter = nCount; qHVZsZ
} [QUaC3l)
} k6eh$*!
<OgwA$abl%
dmA#v:$1
/* PzF>yG[
**Utility.java jEhPx
*/ CZZwBt$P
package NetFox; 28 Q\{Z.
vo(riHH
A; _Zw[
public class Utility { -So$f-y
R` g'WaDk
'_ZiZ4O
public Utility() T8^`<gr.
{ Ob!NC&
&6="r}
VN3[B eH
} ^5E:hW[*
~t+T5`K
//线程睡眠 aFw \w>*^
public static void sleep(int nSecond) kB[l6`
{ pYN.tD FO
try{ h4ozwVA
Thread.sleep(nSecond); Q&5s,)w-
} kF]sy8u]
catch(Exception e) G]v BI=
{ UpTVLx^c
e.printStackTrace (); mY=Q#nG
} c,j[ix
} '8w}m8{y
{<cL@W
//日志 MD98N{+[|
public static void log(String sMsg) E4N/or
{ DbWaF5\yD
System.err.println(sMsg); 1VKu3
} "%(SLQOyy
l"zwH
eQqnPqi-
public static void log(int sMsg) v`r![QpYf
{ -#Bk
System.err.println(sMsg); u_HCXpP!Q
} ]A&pXAM
} k'8tqIUN]
F5y0(=$T
O\J{4EB@.
/* mV'-1
**TestMethod.java NoOrQ m
*/ O2qy[]km
package NetFox; 6nA/LW\x
WhT5NE9t
fK|P144
public class TestMethod { k*4!rWr0r&
%ZsdCQc{`
HT:V;?"
public TestMethod() ^>/~MCyM.
{ ///xx/weblogic60b2_win.exe XjXz#0nR
try{ b|-}?@&7&q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i&TWIl8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cY^'Cj
SiteFileFetch fileFetch = new SiteFileFetch(bean); b($9gre>mI
fileFetch.start(); QQ,V35Vp[
} +mPVI
catch(Exception e){e.printStackTrace ();} }Y"vUl_I2
G\z5Ue*
8kLHQ0pmu
} Hp>_:2O8s
-K (>uV!?
w2SN=X~#
public static void main(String[] args) Z'UhJuD5
{ }Uu#N H
new TestMethod(); hnimd~E52k
} g43(N!@g
} &gF9VY
点击下载更多相关资料