http断点续传简单实现（java)

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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)); I F!xZ6X8
} L,#YP#O,j
for(int i=0;i<nEndPos.length-1;i++) rqN+0CT
{ c)^A|{,G
nEndPos = nStartPos[i+1]; AhOBbss]q
} RPeH[M^
nEndPos[nEndPos.length-1] = nFileLength; v*GS>S
} Zh;}Q(w
} t6KKfb
D60quEe3%
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//启动子线程 URm<Ji
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?_AX;z
for(int i=0;i<nStartPos.length;i++) MDIPoS3BRa
{ @Nh}^D >j
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CUpRtE8@[_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0.R3(O
nStartPos,nEndPos,i); &XCd2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jf7H;ZM<
fileSplitterFetch.start(); iN'T^+um=
} NkBvN\CQ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iExKi1knx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^J7q,tvbJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ['\R4H!x
nEndPos = " + nFileLength); 6q>iPK Jt
// fileSplitterFetch[nPos.length-1].start(); +0ukLc@
.{8[o[w =
Pz2Q]}(w
//等待子线程结束 ~gZ1*8s`
//int count = 0; ]JGq{I>%+6
//是否结束while循环 jsgDJ}
boolean breakWhile = false; ~s'}_5;VY
aDX&j2/
cyWb*Wv
while(!bStop) GR*sk#{
{ Hc\@{17
write_nPos(); h+H+>,N8`
Utility.sleep(500); zJ8T.+qJ
breakWhile = true; ,|\\C6s
ZyNgG9JL]
O_2o/
for(int i=0;i<nStartPos.length;i++) I(BJ1 8F$
{ wY\,b*x
if(!fileSplitterFetch.bDownOver) H*<E5^#dw
{ ke W7pN?
breakWhile = false; r>bgCQ#-n
break; #| gh
} _8 K|2$X
} lj&\F|-i
if(breakWhile) ol_\ "
break; td\gk
8lqmd1v
W!XBuk-
//count++; 3*%+NQIj
//if(count>4) RfvvX$
// siteStop(); 5X];?(VTsb
} Px?"5g#+
u|$HA>F[
A~E S{Zkh
System.err.println("文件下载结束！"); Lhg
} f&5S`}C
catch(Exception e){e.printStackTrace ();} & }j;SK5
} *< fJgc"3
5WfZd
CL5^>.}
//获得文件长度 4PS|
public long getFileSize() p</t##]3ks
{ PEjd
int nFileLength = -1; q*4@d)_&
try{ #huh!Mn
URL url = new URL(siteInfoBean.getSSiteURL()); p%bMfi*T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `]GL3cIh:
httpConnection.setRequestProperty("User-Agent","NetFox"); %|JL=E}%|
V:5aq.o!
m$_l{|4z
int responseCode=httpConnection.getResponseCode(); *tpS6{4=#7
if(responseCode>=400) jc:=Pe!E
{ 4<1V
processErrorCode(responseCode); 0VJHE~Bgi
return -2; //-2 represent access is error >{Mv+
} o\it]B
#H Jlm1d
@ kv~2m
String sHeader; 0;`FS/[(f
o%lxEd r
h'G
for(int i=1;;i++) j<Pw0?~s6
{ [N[4\W!!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0lq?l:/
//Utility.log(in.readLine()); p_n$}z
sHeader=httpConnection.getHeaderFieldKey(i); ;QG8@ms|
if(sHeader!=null) 6_yatq5c
{ ~n0Exw(
if(sHeader.equals("Content-Length")) C{l-l`:
{ Kt]vTn7!9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z{#3-O<a+n
break; `]19}GK~xo
} M!gu`@@}F
} CUC]-]8
else DrBkR`a?
break; jc>B^mqx
} 9$[MM*r
} xo ^|d3
catch(IOException e){e.printStackTrace ();} {s6#h#U
catch(Exception e){e.printStackTrace ();} }NV<k
zU0JwZi
86qQ"=v
Utility.log(nFileLength); Um`KmM3
Ik5-ooZ&{
n2c(x\DA&
return nFileLength; Ha ZV7
} v=dN$B5y3
q:jv9eL.O
lQ[JA[
//保存下载信息（文件指针位置） K'"s9b8
private void write_nPos() =:R${F
{ dYwEVu6q
try{ 6+s&%io4
output = new DataOutputStream(new FileOutputStream(tmpFile)); $j(4FyH\
output.writeInt(nStartPos.length); r}|)oG,=
for(int i=0;i<nStartPos.length;i++) 'f %oL/,
{ 7uv"#mq
// output.writeLong(nPos); Pq-@waH3
output.writeLong(fileSplitterFetch.nStartPos); p ~+sk1[.
output.writeLong(fileSplitterFetch.nEndPos); l% %cU"
} Zcc7 7dRA
output.close(); Ew{N2
} ~<Wa$~oY
catch(IOException e){e.printStackTrace ();} +Ezl.O@z
catch(Exception e){e.printStackTrace ();} I%j]pY4
} 0f+]I=1\
oOXJ7|n
n*|8(fD
//读取保存的下载信息（文件指针位置） /<O9^hA|
private void read_nPos() !#olG}#[
{ 5*B'e{C
try{ n|QA\,=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); QqeF
int nCount = input.readInt(); xw1,Wbu]
nStartPos = new long[nCount]; EW)r/Av:,
nEndPos = new long[nCount]; cZWW[i
for(int i=0;i<nStartPos.length;i++) 4l/~::y
{ .Z17X_
nStartPos = input.readLong(); +@@( C9
nEndPos = input.readLong(); 5':j=KQE_
} <P Vmr2Jp"
input.close(); q}g0-Da
} lKRp9isn^
catch(IOException e){e.printStackTrace ();} >Mm.MNU
catch(Exception e){e.printStackTrace ();} zRau/1Y0
} %uP/v\l
h{)`W ]~
n2F*a
private void processErrorCode(int nErrorCode) &(x>J:b
{ N=8CVI
System.err.println("Error Code : " + nErrorCode); p1z^i(
} lrMkp@f.
d;r,?/C
Z\)P|#L$
//停止文件下载 7:.!R^5H
public void siteStop() |IWm:[H3
{ \/y&l\ k)
bStop = true; cf_X=;yaqy
for(int i=0;i<nStartPos.length;i++) .e S* F
fileSplitterFetch.splitterStop(); )B5U0iIi
"MOmJYH
K<u~[^R
} N,cj[6;T%
} Tl^)O^/
//负责部分文件的抓取 <g8{LG0
**FileSplitterFetch.java <S@2%%W
*/ ;/^O7KM-
package NetFox; t{ridA}
iW?NxP
JQ\o[t
import java.io.*; 3ZYrNul"
import java.net.*; rV I-Yb
`zcpaE.@
:\1vy5 _
public class FileSplitterFetch extends Thread { 34vH+,!u
-r{]9v2j
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String sURL; //File URL {JcMJZ3
long nStartPos; //File Snippet Start Position @Z~0!VY
long nEndPos; //File Snippet End Position Ti5"a<R4m6
int nThreadID; //Thread's ID 3SOrM
boolean bDownOver = false; //Downing is over .noY[P8i
boolean bStop = false; //Stop identical )q%DRLD'G
FileAccessI fileAccessI = null; //File Access interface 9Bu=8P?
hN1{?PQ
|Gb~[6u
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException xSjs+Y;Mu
{ ^`(3X
this.sURL = sURL; X*:)]p(R
this.nStartPos = nStart; )|S!k\^A
this.nEndPos = nEnd; ~eGtoEY
nThreadID = id; -EU~ %/=m+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 nyd'79~>G
} [#2z=Xg
\88IFE
@,q<][q
public void run() 9kU|?JE
{ js=w!q0)9
while(nStartPos < nEndPos && !bStop) *>Zq79TG
{ XZPq4(,9}
(K>4^E8
D)JI11a<
try{ 7(5 wP(
URL url = new URL(sURL); 7:S)J~s*O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _d3/="=
httpConnection.setRequestProperty("User-Agent","NetFox"); Ml,87fo
String sProperty = "bytes="+nStartPos+"-"; I[v~nY~l`
httpConnection.setRequestProperty("RANGE",sProperty); l8!n!sC[,
Utility.log(sProperty); =ThacZHb8
_&F*4t!n_
sMb+4{W&6
InputStream input = httpConnection.getInputStream(); qVJC O-K|
//logResponseHead(httpConnection); ^G(+sb[t
#c2JWDH1F
uTUkRqtD!
byte[] b = new byte[1024]; N6S}u@{J~N
int nRead; qznd'^[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ?$X1X`@
{ 6imQjtI
nStartPos += fileAccessI.write(b,0,nRead); e_CgZ
//if(nThreadID == 1) y+a]?`2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;jpsH?3g
} .AHww7
c ]&|.~2&
c5tCw3$t
Utility.log("Thread " + nThreadID + " is over!"); B976{;QvXV
bDownOver = true; sBu- \P#
//nPos = fileAccessI.write (b,0,nRead); C+c;UzbD
} t[^68]
catch(Exception e){e.printStackTrace ();} @{UtS2L
} l8ZzKb-
} &]HY:
62%=%XD
tdB<
//打印回应的头信息 pD%Pg5p`
public void logResponseHead(HttpURLConnection con) ]W 6!Xw)[
{ n8>(m,
for(int i=1;;i++) q:ZF6o`Z83
{ m]:|j[!*M
String header=con.getHeaderFieldKey(i); th(<S
if(header!=null) @phb5
//responseHeaders.put(header,httpConnection.getHeaderField(header)); BDT1qiC
Utility.log(header+" : "+con.getHeaderField(header)); |Orp:e!
else [CJr8Qn
break; ibskce{H
} 8;]U:tv
} p_2-(n@
|\/Y<_)JD
~!a~ -:#
public void splitterStop() F2RU7o'f.
{ |cCrLa2*-
bStop = true; Aaq!i*y
} 0SLS;s.GX
P mgTTI
s@vHU4
} 3]1uDgfr
W-+~r
%) 8 UyZG
/* bjEm=4FI;
**FileAccess.java &]Q\@;]Aq
*//文件访问(定位，写) !r*Ogv[
package NetFox; \sZ!F&a~
import java.io.*; 0(!D1G{ul
h*9s^`9)
X8(, ,>_
public class FileAccessI implements Serializable{ @e_<OU
=tE7XC3X_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \d#|n u
RandomAccessFile oSavedFile; jN43vHm\Y9
long nPos; &(Ot(.
u*J,3o} <
1FiFP5
public FileAccessI() throws IOException K7H`Yt
{ Y^-faL7*\
this("",0); Cj x(Z]
} NiQ_0Y}
w(KB=lA2
WS?"OTH.^\
public FileAccessI(String sName,long nPos) throws IOException Hjm
{ MxO0#
oSavedFile = new RandomAccessFile(sName,"rw"); yBwgLn
this.nPos = nPos; 'X$2gD3c9
oSavedFile.seek(nPos); g~JN"ap
} %4~2
],HF)21
.Bu?=+O~
public synchronized int write(byte[] b,int nStart,int nLen) ({}JvSn1
{ eS/4gM7%
int n = -1; 3"Y |RSy
try{ N>S_Vgk}
oSavedFile.write(b,nStart,nLen); nDvj*lZF
n = nLen; '%$)"g]/#
} CG(G){u&
catch(IOException e) bZ.q?Hlfk
{ P<@V
e.printStackTrace (); e-dpk^-
} O%.c%)4Xo
"[ 091<
D/1f>sl
return n; nmn 8Y V1
} R7)2@;i
_S[@d^cY
jF}u%T)HL
} spE(s%dgL
BuE=(v2}
Tq7cZe"6
/* u"*@k^}(
**SiteInfoBean.java '7UW\KEB[}
*/ yrnIQu*Uu
package NetFox; %,G&By&,
ppjS|l*`
4]F:QS% x
public class SiteInfoBean { #&A)%Qbg
%B&y^mZv*\
U=4tJb
private String sSiteURL; //Site's URL DRC2U%[
private String sFilePath; //Saved File's Path -Q6njt&
private String sFileName; //Saved File's Name ]\y:AkxhJ
private int nSplitter; //Count of Splited Downloading File b'Scoa7@'
tp-PE?
~9Nn8g6
public SiteInfoBean() gi|j! m
{//nSplitter的缺省值为5 06FBI?;|=
//default value of nSplitter is 5 b42"Y,sbB
this("","","",5); h#ogL-UU
} mlsM;Ad2
&> Myf@
tCFXb6Cz
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "Cz8nG
{ ~@=*JzP?
sSiteURL= sURL; G(2(-x"+
sFilePath = sPath; vKv!{>,v9Z
sFileName = sName; DM3W99PWA
this.nSplitter = nSpiltter; A.@S>H'P
biJ"@dm 4
'gDhi!h%
} gq|T:
dD Qx[
)*=ds,
public String getSSiteURL() .</`#
{ w%(Ats
return sSiteURL; G1t{a:
} /1F5khN
2UPqn#.3
6 XZF8W
public void setSSiteURL(String value) nU{}R"|
{ `*5_`^t
sSiteURL = value; /0PBY-O
} ^XsIQz[q
TC7Rw}jF
j:)"s_
public String getSFilePath() [YbnpI
{ MlDWK_y_&
return sFilePath; hmfO\gc}y
} 5C}1iZEJ
~(( '1+
IkzY
public void setSFilePath(String value) _O76Aw-@l
{ Sm@T/+uG:
sFilePath = value; R!mFMw"
} Y7TW_[_u
3ZZ"mlk*
'jr\F2
public String getSFileName() 'G6g yO/K
{ I\%a<
return sFileName; ;}iV`)S
} p~/
;7jszs.6%
}Zs y&K
public void setSFileName(String value) nH6Ny
{ ia'eV10
sFileName = value; u0&QStI
} i%M6$or
JDTlzu1hR
8zDLX,M-
public int getNSplitter() Fj?gXc5{
{ ID/=YG@
return nSplitter; {yo<19kV@
} !p&[:+qN
p$mx
sqtMhUQ?>w
public void setNSplitter(int nCount) q%g!TFMg
{ v}vwk8
nSplitter = nCount; l70a&[W
} avJ%J"j8z
} 8`QbUQ6
,".1![b
qL;OE.?oA
/* P2U^%_~
**Utility.java ""0 cw
*/ _,,w>q6K
package NetFox; 2P`Z>_
:5YL!D/&
DZ-2Z@{PX
public class Utility { C;mcb$@
Pv- i.
reBAxmt
public Utility() ~pv|
{ Y(a0*fh
>s5i
AQx:}PO
} Y@jO#6R
v[++"=< o8
//线程睡眠 J@CKgE
public static void sleep(int nSecond) F.]D\"0`
{ M<nKk#!+h
try{ ';>]7oT`
Thread.sleep(nSecond); h83W;s
} <$"
catch(Exception e) U]o
{ zJ"`40V*;
e.printStackTrace (); U=kPxe
} e7n[NVrX
} <8 $fo
r]sNI[
//日志 S.4gfY
public static void log(String sMsg) DlMT<ld
{ | e?:Uq
System.err.println(sMsg); ^~ 95q0hq:
} IqA'Vz,lL
IBT1If3
j aU.hASj
public static void log(int sMsg) rEoMj)~\4&
{ bgk+PQ#S-
System.err.println(sMsg); rpB0?h!$
} X[e:fW[e)
} [C>>j;q%
AGWs>
xWiR7~E
/* fk6`DUBV
**TestMethod.java ^\(<s
*/ tgR4C#a
package NetFox; Bu]PNKIi
a3f-9LN
hw @)W
public class TestMethod { Rj'Tu0l
(XU(e
Bn4wr
public TestMethod() '{ $7Dbo
{ ///xx/weblogic60b2_win.exe aVE/qXB
try{ *!m\%*y{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); iaV%*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~Y_5q)t(
SiteFileFetch fileFetch = new SiteFileFetch(bean); [C0"vOTUb
fileFetch.start(); X_\$hF
} PwC9@c%c
catch(Exception e){e.printStackTrace ();} |7$Q'3V
B-1Kfc
D;Bij=
} ~WW!P_wI,
fe3a_gYPz
\cr)O^&
public static void main(String[] args) w$evAPuz^
{ ['%$vnS5S
new TestMethod(); pXhN?joe
} ] >4CBm$
} Fd1t/B,
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