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)); Mi.2 >
} I?D=Q$s
for(int i=0;i<nEndPos.length-1;i++) ="]r{
{ .<QKQ%-
nEndPos = nStartPos[i+1]; :.AC%'S
} 3Y#
nEndPos[nEndPos.length-1] = nFileLength; WILa8"M
} f.J^HQ_
} o+hp#e
!X7z y9
=k<b* 8
//启动子线程 O;4S<N
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; eWqS]cM#
for(int i=0;i<nStartPos.length;i++) \{<ml n
{ D-@6 hWh~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4-[U[JJc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5P<"I["
nStartPos,nEndPos,i); ?H8w;Csq-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4e>f}u5
fileSplitterFetch.start(); 5)f 'wVe
} H%m^8yW1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), huv|l6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a"P & 9c
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Fw[1Aa#
nEndPos = " + nFileLength); 6?}|@y^fb
// fileSplitterFetch[nPos.length-1].start(); ,2!7iX
1.p?1"4\u
BsXF'x<U*
//等待子线程结束 P4"BX*x
//int count = 0; ij]~n
//是否结束while循环 9HR1m3
boolean breakWhile = false; ;s,1/ kA
HAE$Np|>a
J37vA zK%
while(!bStop) pm+E)z6Yo
{ w@2NXcmw
write_nPos(); w +UBXW
Utility.sleep(500); 4;~xRg;u&*
breakWhile = true; ww %c+O/
br88b`L
:@&e~QP(
for(int i=0;i<nStartPos.length;i++) JGq9RB]D$
{ @8J*vY =e
if(!fileSplitterFetch.bDownOver) G?F!Z"S
{ X_-/j.
breakWhile = false; IrRy1][Qr
break; T#rUbi>""
} &O+S[~
} |b@`ykD
if(breakWhile) /b{@']
break; #pRbRT9
dj084q7
H)TKk%`7
//count++; GKg #nXS
//if(count>4) JqLPJUr
// siteStop(); *RJD^hu
} A\mSS
XU"G
IH*G7;
System.err.println("文件下载结束！"); {>9<H]cSP
} w,6gnO
catch(Exception e){e.printStackTrace ();} g NE"z
} uUaDesz~=
a$uDoi
6G4~-_
//获得文件长度 [D|Uwq
public long getFileSize() M&Q&be84
{ uAYDX<Ja9
int nFileLength = -1; 0Q>
try{ FFwu$S6e
URL url = new URL(siteInfoBean.getSSiteURL()); HRahBTd(z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BpFXe7
httpConnection.setRequestProperty("User-Agent","NetFox"); Y"5FK
@pvQci
A5fzyG
int responseCode=httpConnection.getResponseCode(); Kk.\P|k2
if(responseCode>=400) 'yOx&~H]
{ #( 4)ps.
processErrorCode(responseCode); C]ho7qC
return -2; //-2 represent access is error qzY:>>d'
} sFk{Tv@Yz
'u PI~l`g
uG.`
String sHeader; @B+8' b$9
|&S^L}V.C
h{]0 H'g
for(int i=1;;i++) =*(_sW6;
{ Xhyc2DKa_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); e'|P^G>g
//Utility.log(in.readLine()); FzsW^u+
sHeader=httpConnection.getHeaderFieldKey(i); +A 6kw%"
if(sHeader!=null) "5,Cy3
{ ?)qm=mebY
if(sHeader.equals("Content-Length")) 0a?[@ -Sz
{ *Q-uE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); vO zUAi
break; S2I{?y&K
} >r:z`^p
} o9D#d\G
else S="\S
break; OlW5k`B
} X|TGM
} SX?hu|g_r
catch(IOException e){e.printStackTrace ();} `sdbo](76
catch(Exception e){e.printStackTrace ();} w&^Dbme
U&+lw=
)1 0aDTlr
Utility.log(nFileLength); QSYKYgxC
a$11u.\q+
PVq y\i
return nFileLength; pkIJbI{aS
} g>?,,y6/w
&fxyY(
cpq0'x\
//保存下载信息（文件指针位置） ]x_14$rk
private void write_nPos() oe_,q&e
{ Q`h@-6N
try{ 5zJ#d}%}S"
output = new DataOutputStream(new FileOutputStream(tmpFile)); [HRP&jr
output.writeInt(nStartPos.length); Xs4G#QsAJ
for(int i=0;i<nStartPos.length;i++) r)w]~)8
{ L~M6ca"
// output.writeLong(nPos); Gnqun%
output.writeLong(fileSplitterFetch.nStartPos); ]waCYrG<sY
output.writeLong(fileSplitterFetch.nEndPos); <ot%>\C
} :;3y^!
output.close(); rYyEs I#qo
} g3w-Le&T
catch(IOException e){e.printStackTrace ();} nza^<DlS
catch(Exception e){e.printStackTrace ();} SP|Dz,o
} Wf *b"#
wqn}t]
wGpw+O
//读取保存的下载信息（文件指针位置） 4y9n,~Qgw
private void read_nPos() l0wvWv*k
{ Q0_|?]v
try{ ;cZ]^kof
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bJ.68643
int nCount = input.readInt(); 4d]T`
nStartPos = new long[nCount]; ])T_&%
nEndPos = new long[nCount]; t7$2/C
for(int i=0;i<nStartPos.length;i++) }~Y#N
{ 0c:jwtf
nStartPos = input.readLong(); 7[7Sm^Tw
nEndPos = input.readLong(); WkY>--^
} ~F]If\b
input.close(); 0>?78QL9<
} ~ @s$
catch(IOException e){e.printStackTrace ();} ;Q8rAsf9
catch(Exception e){e.printStackTrace ();} 8:UV;5@
} <7~+ehu
N5GQ2V
-}<W|r
private void processErrorCode(int nErrorCode) cW, 6MAQo
{ R$40cW3`
System.err.println("Error Code : " + nErrorCode); ^pZ\:
} =kWm9W<^
|FD-q.AV
!*|`-woE
//停止文件下载 %xI,A'#
public void siteStop() Si%K|$?@
{ tB{O6=q
bStop = true; LMte,zs>
for(int i=0;i<nStartPos.length;i++) a@WSIcX*W
fileSplitterFetch.splitterStop(); 8h7z
itIzs99j
5eSmyj-W
} 9G}Crp
} {-Y% wM8<i
//负责部分文件的抓取 xyTjK.N
**FileSplitterFetch.java GCPSe A~cx
*/ HveOG$pT
package NetFox; DJhCe==$v
IE9A _u*
xk5Z&z
import java.io.*; 7L&=z$U@m
import java.net.*; G8oOFBQD
{oN7I'>
i50^%,
public class FileSplitterFetch extends Thread { 8MPXrc,9-
{e8.E<f-
+3D3[.n
String sURL; //File URL 9y"*H2$#
long nStartPos; //File Snippet Start Position 7w{>bYP
long nEndPos; //File Snippet End Position PYz^9Ud 6g
int nThreadID; //Thread's ID lGZ^ 8
boolean bDownOver = false; //Downing is over kC)ye"r
boolean bStop = false; //Stop identical u=h/l!lR
FileAccessI fileAccessI = null; //File Access interface W.u}Q@
Gvw:h9v
eu|cQ^>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Y/_b~Ahn
{ IGd]!
this.sURL = sURL; _(s|@UT#
this.nStartPos = nStart; @{!c [{x,T
this.nEndPos = nEnd; >*%mJX/F
nThreadID = id; E5G=Kh[NP
fileAccessI = new FileAccessI(sName,nStartPos);//定位 jE</a%
} 1Lb+ &
`8%2F}x}qD
;u0MY
public void run() $k|k5cP8x
{ dRXF5Ox5K}
while(nStartPos < nEndPos && !bStop) 1x#Z}XG
{ hqVFb.6[
{?' DZR s
V'4sOn
try{ Q}M% \v
URL url = new URL(sURL); Yvu!Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \j]i"LpWb
httpConnection.setRequestProperty("User-Agent","NetFox"); 0x\bDWZ_
String sProperty = "bytes="+nStartPos+"-"; gUB%6vG\I
httpConnection.setRequestProperty("RANGE",sProperty); -&* 4~
Utility.log(sProperty); OXuBtW*,z+
q8{)27f,
257pO9]
InputStream input = httpConnection.getInputStream(); %P2GQS-N
//logResponseHead(httpConnection); wBUn*L
r-s.i+\
~P85Or
byte[] b = new byte[1024]; s1xl*lKX%
int nRead; V!F# ek:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <m#ov G6
{ "$*&bC#dE
nStartPos += fileAccessI.write(b,0,nRead); xFt[:G`\}u
//if(nThreadID == 1) 2n]Br
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I|*w?i*
} emo@&6*
}0Qex=vkO
[Az<E3H"
Utility.log("Thread " + nThreadID + " is over!"); /L8Q[`;.
bDownOver = true; ?[}r& f
//nPos = fileAccessI.write (b,0,nRead); Yp1;5Bbp
} e:E:"elr]
catch(Exception e){e.printStackTrace ();} sF$$S/b
} 25RFi24>D
} 1o. O]>
qJb9JL$s
6.| {l8%r
//打印回应的头信息 :O}=$[
public void logResponseHead(HttpURLConnection con) i"~J -{d}
{ ]CD
for(int i=1;;i++) 'Tni;
{ m?]XNgT
String header=con.getHeaderFieldKey(i); =1noT)gCR
if(header!=null) I5l5fx
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )DS|mM)
Utility.log(header+" : "+con.getHeaderField(header)); r wtU@xsD
else /G`'9cD
break; 3,2|8Q,((!
} E({W`b~_f
} < `r+ZyM
=ILE/pC-|
*"\QR>n
public void splitterStop() fD<9k
{ Fy^=LrH=D
bStop = true; LE!xj 0
} Tji G!W8
qU(,q/l
3xSt -MA
} |N%?7PZ(
fz[o;GTc
kQ5mIJ9(
/* LD]a!eY
**FileAccess.java slC 38
*//文件访问(定位，写) U_t[J|
package NetFox; #1-,s.)
import java.io.*; a\60QlAk~
6;WfsG5
uIOnP
public class FileAccessI implements Serializable{ ?/Bp8q(
)N4!zuSVf
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 K( : NshM
RandomAccessFile oSavedFile; ]W^F!p~eC
long nPos; N?Byp&rqI<
o gec6u}
5eP8nn.D
public FileAccessI() throws IOException hXBAs*4DV8
{ i^SuVca
this("",0); V*X6 <}
} OPVF)@"ptM
k1l\Rywp
kjVUG >e>
public FileAccessI(String sName,long nPos) throws IOException cZB?_[Cp
{ tk'1o\@p9b
oSavedFile = new RandomAccessFile(sName,"rw"); rucgav
this.nPos = nPos; N8hiv'3
oSavedFile.seek(nPos); I$.HG]
} w$Zi'+&*
0wM2v[^YO
c2Q KI~\x
public synchronized int write(byte[] b,int nStart,int nLen) q~esxp
{ T?vM\o%i3
int n = -1; s!WGs_1@
try{ ?VUU[h8"v5
oSavedFile.write(b,nStart,nLen); k!?sHUAj
n = nLen; d}@b 3
} K/xn4N_UX
catch(IOException e) 99<]~,t=5
{ Gw!VPFV>W
e.printStackTrace (); sIUhk7Cd8
} =35g:fL
oT76)O
uX82q.u_y
return n; %.k~L
} 52X[{
BK$cN>J
&B1j,$NRc
} b#~K>
5&59IA%S
4eFqD;
/* LxdF;JCz:
**SiteInfoBean.java Y~E 8z
*/ `_YXU
package NetFox; srzlr-J
$('"0 @fg
i}u,_ }
public class SiteInfoBean { (AYzN3 ?D
b+=@;0p*6B
!wbO:py[8>
private String sSiteURL; //Site's URL O*Gg57a
private String sFilePath; //Saved File's Path s2Z'_rT
private String sFileName; //Saved File's Name #:B14E
private int nSplitter; //Count of Splited Downloading File )RUx
` nd/N#
Qy4eDv5
public SiteInfoBean() eELLnU{"
{//nSplitter的缺省值为5 d-X6yRjnj
//default value of nSplitter is 5 8dPDs#Zl
this("","","",5); xG_LEk( zD
} M `O=rH }
rY?]pMp
v2Ft=_*G|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) o#Gf7.E8
{ 6Qc *:(GE
sSiteURL= sURL; $jkzm8{W
sFilePath = sPath; :@rq+wvP
sFileName = sName; Lm-f0\(
this.nSplitter = nSpiltter; 83(-/y
Z;ze{Vb
v(0IQ
} *A&A V||q
ylGT9G19
"?*B2*|}`
public String getSSiteURL() FhP$R}F
{ $)YalZ
return sSiteURL; "xI70c{
} QLm#7ms*y
,+P2B%2c
wC>}9OM
public void setSSiteURL(String value) 7v']wA r]
{ Wq2Bo*[*
sSiteURL = value; ~|Nj+A
} 2%?Kc]JY9
2S
7+NBcZuG9
public String getSFilePath() awU!3)B
{ (^HU|
return sFilePath; ~XeWN^l(Ov
} <)$e*HrI
XQ'$J_hC
,Gi%D3lA
public void setSFilePath(String value) \? n<UsI
{ u5.zckV
sFilePath = value; Leu6kPk
} $RA+StF!]
SpO%nZ";g8
01n7ua*XX
public String getSFileName() f8?hEa:js
{ 1Y:JGon
return sFileName; ?vBMx _0
} H2S/!Q;K
$jg~a
RRb>]oD
public void setSFileName(String value) H73 r3BH
{ Pk3b#$+E
sFileName = value; gJH^f3
} 79z/(T+
t`- [
'WNq/z"X
public int getNSplitter() LVaJyI@/>
{ v8"Zru
return nSplitter; z8dBfA<z
} 'F%h]4|1
;S9 z@`a.
XZ=%XB:?
public void setNSplitter(int nCount) M?00n< vM
{ =B{B?B"r
nSplitter = nCount; =TGa\iclpB
} );/p[Fd2]
} e +Ikw1y"f
*x/H
+ovT?CMo
/* R('\i/fy
**Utility.java 'kSm}}y
*/ ~}_S]^br
package NetFox; Sa-" G`
F AQx8P
k?}y@$[)
public class Utility { Ou_2UT
Obx!>mI^6
@rv)J[7Y&
public Utility() F]L96&
{ ?BX}0RWMh7
m f\tMik<
nKmf#
} '=+gweM
M4n0GWHLy
//线程睡眠 Cb6K!5[q]
public static void sleep(int nSecond) *qJHoP;
{ pwvmb\
try{ ,z01*Yx
Thread.sleep(nSecond); x21XzGLY|}
} GMY[Gd
catch(Exception e) <Zo{D |hW
{ -;O"Y?ME
e.printStackTrace (); [1l OGck[
} $Ji;zR4,
} ,T-xuNYC
b%h.>ij?
//日志 B2:GGZ|jS
public static void log(String sMsg) q26qY5D
{ GBTwQYF
System.err.println(sMsg); 9aYVbq""
} k/M{2Po+
:7*9W|e
H~?7:K
public static void log(int sMsg) BxiR0snf0q
{ DFbhy
System.err.println(sMsg); sVH w\_F$
} Ri3*au/Q
} h^YUu`P
yJ>Bc
g'9~T8i& ^
/* 4,&f#=Y
**TestMethod.java 1*f/Y9 Z
*/ ?jsgBol
package NetFox; JF'<""
PB)vE
/vPr^Wv
public class TestMethod { ^SbxClUfw!
s)+] pxV0-
e35")z~
public TestMethod() %NcBq3
{ ///xx/weblogic60b2_win.exe braI MIQ`
try{ j>5X^Jd
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %v0;1m
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ";upu
SiteFileFetch fileFetch = new SiteFileFetch(bean); xg4wtfAbS
fileFetch.start(); )Wk&c8|y
} ?weuq"*a
catch(Exception e){e.printStackTrace ();} }%c0EY'
EgRuB@lw76
Rsx?8Y^5
} -,ojZFyRi
Y}h&dAr
39x 4(
public static void main(String[] args) %6x3G
{ Knp}88DR^j
new TestMethod(); 59(kk;
} w6ck wn,
} 4 g8t
点击下载更多相关资料