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)); <Ys7`e6eY
} cq9d;~q
for(int i=0;i<nEndPos.length-1;i++) :fQN_*B4@4
{ Fl++rUT
nEndPos = nStartPos[i+1]; p<&dy^mS
} N|w;wF!3
nEndPos[nEndPos.length-1] = nFileLength; soqnr" 1
} wD SSgk
} Mm%b8#Fe!
xI8v'[3
e*o:ltP./
//启动子线程 F8B:P7I
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8},fu3Z
for(int i=0;i<nStartPos.length;i++) JB HnJm
{ mWuhXY^Q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D1EHT}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), t}gK)"g
nStartPos,nEndPos,i); Co`:D
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kv`5"pa7M
fileSplitterFetch.start(); +'UxO'v3]
} t_Ul;HVPS
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +Q!Kj7EU/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (ewcj\l4*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", IXsOTBM
nEndPos = " + nFileLength); "~T06!F45
// fileSplitterFetch[nPos.length-1].start(); a2H_8iQ!
Q]-r'pYr
)==Qo/N:
//等待子线程结束 K555z+,'e
//int count = 0; ; .hTfxE0
//是否结束while循环 5S4`.'
boolean breakWhile = false; >|JMvbje
sE0,b
7` t,
while(!bStop) ? \NT'CG
{ E9j(%kQ2
write_nPos(); eb<'>a
Utility.sleep(500); g=s2t"&
breakWhile = true; X($@E!|
,@t#)HV
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for(int i=0;i<nStartPos.length;i++) v9Ez0 :)
{ 0*o=JM]
if(!fileSplitterFetch.bDownOver) 'Y5=A!*@tf
{ 62#8c~dL
breakWhile = false; CvqUaHW@
break; ;sd] IZ$#
} YHr<`Q</
} 5fK<DkB$>:
if(breakWhile) vo2TP:
break; Dz+R Q`Vn
<(Ktf0'__
V,:~FufM^
//count++; ]j<& :_
//if(count>4) m ,TYF
// siteStop(); ooT~R2u
} 5v#_2Ih
{4b8s%:!4
<nn!9V\C
System.err.println("文件下载结束！"); SMh[7lU`
} JP 8v2) p
catch(Exception e){e.printStackTrace ();} mC84fss
} 1iE*-K%Q
k!m9 l1x
K|-RAjE
//获得文件长度 vC5y]1QDd
public long getFileSize() eh$T 3_#q
{ q.PXO3T
int nFileLength = -1; L!kbDbqn
try{ Ib$?[
URL url = new URL(siteInfoBean.getSSiteURL()); ;EfREfk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xsXf_gGu
httpConnection.setRequestProperty("User-Agent","NetFox"); )"<:Md$7
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{NV=k%MTmi
int responseCode=httpConnection.getResponseCode(); -Tr*G4
if(responseCode>=400) Q?W}]RW
{ 1FmVx
processErrorCode(responseCode); cGe-|>:
return -2; //-2 represent access is error JU0|pstf
} ^ZO3:"t!w
`Yc>I!iN
X !l#1
String sHeader; -j"2rIl4#
5}2XnM2
aD8r:S\
for(int i=1;;i++) [7SR2^uf<j
{ =%oKYQ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); j0[9Cj^%c
//Utility.log(in.readLine()); RDQK_Ef:
sHeader=httpConnection.getHeaderFieldKey(i); A+F@JpV
if(sHeader!=null) 8Wyv!tL
{ I;Bcim;
if(sHeader.equals("Content-Length")) OAtn.LU
{ Tta+qjr
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @60/IE{-v
break; -m>ng E~q
} qW:\6aEG
} x$aFJCL
else /|{~GD +A&
break; 9`sIE_%+
} .(2ui~ed
} $qj||zA
catch(IOException e){e.printStackTrace ();} Md,KW#
catch(Exception e){e.printStackTrace ();} o9uir"=
(.B+U'6
Ndr4e?Xa,
Utility.log(nFileLength); {H%1sI
;]Bkw6o
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return nFileLength; Nb@zn0A(;
} %QrpFE5V5
>R}p*=J
9q!./)
//保存下载信息（文件指针位置） xBi``x2eY
private void write_nPos() ]QAMCu(>
{ 9~$'?
try{ Gfn?1Kt{
output = new DataOutputStream(new FileOutputStream(tmpFile)); )s4a<Sc]
output.writeInt(nStartPos.length); itW~2#nJz
for(int i=0;i<nStartPos.length;i++) seo.1.Da2
{ }~`l!ApD
// output.writeLong(nPos); j-j,0!T~b
output.writeLong(fileSplitterFetch.nStartPos); )YP9
output.writeLong(fileSplitterFetch.nEndPos); Yn }Ivg
} " tUF,G(<
output.close(); IF$*6 ,v.z
} &%4*~;o
catch(IOException e){e.printStackTrace ();} *(sFr E
catch(Exception e){e.printStackTrace ();} w*"h#^1z
} E<XrXxS1O
g}=opw6z
<rpXhcR
//读取保存的下载信息（文件指针位置） @Iy&Qo
private void read_nPos() )~l`%+
{ @-QDp`QtI
try{ ,a/<t"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Cn>RUGoUsI
int nCount = input.readInt(); D#G(&<Q
nStartPos = new long[nCount]; Lcpz(W^
nEndPos = new long[nCount]; Y^@Nvt$<K
for(int i=0;i<nStartPos.length;i++) 1WW`%
{ R s)Nz< d
nStartPos = input.readLong(); dLnMd0
nEndPos = input.readLong(); =Wj{J.7mf]
} O}IRM|r"
input.close(); x<%V&<z1g
} Lk~aMbw#
catch(IOException e){e.printStackTrace ();} }\Mmp+<
catch(Exception e){e.printStackTrace ();} >'X[*:Cx
} 60 z =bd]
o|BEY3|
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private void processErrorCode(int nErrorCode) ir ^XZVR
{ wNgS0{}&`
System.err.println("Error Code : " + nErrorCode); ayQB@2%
} ;K9rE3
oH|<(8efD
zn@yt%PCV
//停止文件下载 +(|6Wv
public void siteStop() JxM[LvVi
{ cc^[u+
bStop = true; $m-rn'Q
for(int i=0;i<nStartPos.length;i++) h!L6NS_Q,
fileSplitterFetch.splitterStop(); zU)Ib<$
4D-4BxN*
H_CX5=Nq^
} nmZJ%n
} y`OL^D4
//负责部分文件的抓取 06#40-
**FileSplitterFetch.java )6 _+
*/ 4/tp-dBip
package NetFox; PV_q=70%T
w_hGWpm
7FiQTS B:
import java.io.*; xiW;Y{kZ
import java.net.*; s;;"^5B.
T$ )dc^
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public class FileSplitterFetch extends Thread { ZRd,V~iz
ZOK,P
Dqw?3 KB
String sURL; //File URL S EeDq/h
long nStartPos; //File Snippet Start Position eQRY xx{
long nEndPos; //File Snippet End Position Mh+ym]6\(k
int nThreadID; //Thread's ID kr|u ||
boolean bDownOver = false; //Downing is over >$yqx1=jW
boolean bStop = false; //Stop identical DVWqrK}q
FileAccessI fileAccessI = null; //File Access interface CI )89`
k7gm)}RKcu
DJmT]Q]o)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <+oTYPgD9
{ 9a*}&fL[
this.sURL = sURL; @N-P[.qL"
this.nStartPos = nStart; J~jR`2+r
this.nEndPos = nEnd; %fyah}=
nThreadID = id; /bd1Bi
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LPNJuz
} u#l@:p
8sG0HI$f+
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public void run() :6*FnKD
{ ;m+*R/
while(nStartPos < nEndPos && !bStop) 0;kp`hB
{ $#/-+>
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2C!Ko"1Y'
try{ )lo;y~ o
URL url = new URL(sURL); 2V1|b`b#4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BSGC.>$s
httpConnection.setRequestProperty("User-Agent","NetFox"); yRZb_Mq9U
String sProperty = "bytes="+nStartPos+"-"; VNmQ'EuV}2
httpConnection.setRequestProperty("RANGE",sProperty); 5IPZ;
Utility.log(sProperty); !Cpy )D(
x@ZxV*T^
O7_u9lz2
InputStream input = httpConnection.getInputStream(); R4V~+tnbG&
//logResponseHead(httpConnection); v?U;o&L(
xSQ:#o=8G
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byte[] b = new byte[1024]; {v,O
int nRead; ue5C ]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E26zw9d
{ Sl8A=Ez
nStartPos += fileAccessI.write(b,0,nRead); P)2.Gx/
//if(nThreadID == 1) NRM=0-16u$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VoOh$&"M
} \!erP!$x.
KL8G2"Z
2k}" 52
Utility.log("Thread " + nThreadID + " is over!"); P@m_tA%
bDownOver = true; )e$}sw{t
//nPos = fileAccessI.write (b,0,nRead); |(Bc0sgw}
} 3Vu_-.ID
catch(Exception e){e.printStackTrace ();} $fhb-c3
} r{V=)h
} %V+hm5Q
0.9%m7.m
f8T6(cA
//打印回应的头信息 Eu4-=2!4
public void logResponseHead(HttpURLConnection con) =peodj^
{ fr\"MP
for(int i=1;;i++) H}R/_5g
{ fq@r6\TI
String header=con.getHeaderFieldKey(i); zJH#J=O
if(header!=null) B~[QmK
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]Cfjs33H
Utility.log(header+" : "+con.getHeaderField(header)); OM]d}}=Y
else s7A3CY]->
break; 4pin\ZS:C
} 29xm66
} x.+r.cAXH
tJ{3Z}K
']N1OVw^vf
public void splitterStop() -A?6)ggf.
{ xp!MA
bStop = true; 56;^ NE4
} /Ria"lLv
% Rv;e
e;M#MkP7
} 8QYP\7}o
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)(?,1>k`Z
/* +[JvpDv%
**FileAccess.java ^/0c`JG!x
*//文件访问(定位，写) AG3iKk??T
package NetFox; m#\I&(l+
import java.io.*; [9wuaw"~[Z
lo1<t<w`
D#=$? {w
public class FileAccessI implements Serializable{ }#u.Of`6"
b6`_;Z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =RA8^wI
RandomAccessFile oSavedFile; D%=VhKq
long nPos; H2ZRUFu
;qA(!`h+
~o_zV'^f@o
public FileAccessI() throws IOException ?5N7,|K)
{ pk%%}tP<
this("",0); eHQS\n
} q X"Pg
qhdY<[6
DRDn;j
public FileAccessI(String sName,long nPos) throws IOException 6.!aJJLN
{ V0rS^SAF
oSavedFile = new RandomAccessFile(sName,"rw"); { ]*#WU
this.nPos = nPos; :i?7RouO
oSavedFile.seek(nPos); x1@`\r#0
} 4Bn <L&@/
}f l4^F
S%^*h{9u"
public synchronized int write(byte[] b,int nStart,int nLen) %kHeU=
{ 0eGz|J*7
int n = -1; $ $=N'Q
try{ c:J;Q){Xz
oSavedFile.write(b,nStart,nLen); ii3{HJ*C
n = nLen; \ah.@s
} A~@u#]]<n
catch(IOException e) {RmN1'%
{ W~!uSrY
e.printStackTrace (); lYF~CNvE
} m@Q%)sc)
c%jW'
CeZ+!-lG
return n; S'h{["P~ 0
} q':P9o*N?
=tKb7:KU
(GeOD V?U
} ^$!H|
P^)J^{r
Z\\'0yuY(
/* ^Fn~@'
**SiteInfoBean.java B24,;2J
*/ _^k9!Vjo
package NetFox; @@1Sxv_
`|rr<Tsy\
[U^@Bkh
public class SiteInfoBean { R5,ISD +s
kKFhbHUZa
(}4]U=/nV
private String sSiteURL; //Site's URL h1(GzL%i_
private String sFilePath; //Saved File's Path +o4W8f=Ga
private String sFileName; //Saved File's Name fz[-pJ5[
private int nSplitter; //Count of Splited Downloading File _Nx#)(x
o^\L41x3
C$<['D?8
public SiteInfoBean() 1MPn{#Ff
{//nSplitter的缺省值为5 J"$Y`;
//default value of nSplitter is 5 x1O]@Z{d\
this("","","",5); M[= #%U3*N
} !eC]=PoY
O>M4%p
#~I.F4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 'QP~uK
{ q83!PI
sSiteURL= sURL; !&f>,?wlP
sFilePath = sPath; (2l?~CaK
sFileName = sName; @hG]Gs[,o
this.nSplitter = nSpiltter; OsGKlWM/
dfa^5`_
sN8)p%'Lg
} vJ a?5Jr
*#| lhf'
VGVb3@
public String getSSiteURL() ImG7E w
{ jgyXb5GY
return sSiteURL; skeXsls
} H!81Pq~
rHMr8,J;
c+bOp 05o-
public void setSSiteURL(String value) 6a%dq"5 +
{ FRR`<do5$,
sSiteURL = value; 9EU0R H
} s6YnNJ,SK
ukAE7O(W&
:W6R]y
public String getSFilePath() 7xlarns
{ v6#i>n~x,
return sFilePath; qJyGr ?
} }TDoQ]P
C}D\^(nLu.
VmbfwHRWb
public void setSFilePath(String value) b;~?a#Z}
{ +p\+15
sFilePath = value; #$?!P1
} @krh<T6|
U'Mxf'q
=*\(Y(0
public String getSFileName() xfFsW^w
{ z"PU`v
return sFileName; Vgg'5o&.
} C U 8s*
: 6|nXL
j +u3VP
public void setSFileName(String value) i9O;D*
{ 7&>==|gt
sFileName = value; vkK8D#K
} *`WD/fG
'#ow9w+^
-n#fj;.2_
public int getNSplitter() P6~&,a
{ 5W4Tp% Lda
return nSplitter; )"sJaHx<
} v9K=\ j
/@xL {
-q")qNt.
public void setNSplitter(int nCount) 1!"iN~
{ _2Hehw
nSplitter = nCount; YX,xC-37y
} mzH3Q564
} &3~_9+
A` )A=L
eZ`x[g%1
/* tFrNnbmlQ
**Utility.java \O G`+"|L
*/ _WB*ArR
package NetFox; CWx_9b zk
dxk~
1_MaaA;ow"
public class Utility { DMpNmF>
FXO{i:Zo
kgGMA 7Jy
public Utility() wNtPh&
{ "}ZUa~7
&l;wb.%ijW
_2p D
} K!A;C#b!
skzTw66W.
//线程睡眠 M?I^Od'8
public static void sleep(int nSecond) 96P3B}Dk
{ ~z&Ho
try{ 9{Xh wi)z
Thread.sleep(nSecond); |*te69RX
} 5 cz6\A&
catch(Exception e) 97-=Vb
{ 3uJ>:,~r
e.printStackTrace (); =cKrp'
} T.B}k`$
} *R8qnvE\()
M7. fz"M
//日志 DFN
public static void log(String sMsg) EhK~S(r^
{ FtmI\,
System.err.println(sMsg); H;kk:s'
} @(I)]Ca%O
snti*e4"V
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public static void log(int sMsg) yIG*
{ 0OF]|hH
System.err.println(sMsg); O od?ifA
} l~j{i/>
} GkYD:o=qx
`bMwt?[*
Q~>="Yiu
/* QbG`F8dj
**TestMethod.java b_%W*Q
*/ C=!YcJ9
package NetFox; p({)ZU3
n.tJ-l5[
O$$$1VHYo
public class TestMethod { NUb:5tL
+8eW/Bs@2
+E8}5pDt
public TestMethod() e_z"<yq
{ ///xx/weblogic60b2_win.exe ns;nle|m
try{ IP-}J$$1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jSMs<ox
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [X=J]e^D
SiteFileFetch fileFetch = new SiteFileFetch(bean); @ 9q/jv`
fileFetch.start(); ^iz2=}Q8
} w/Ej>OS
catch(Exception e){e.printStackTrace ();} avwhGys#
;y%C\YB#
HS[N]'dc
} gW_^GrKpI
uU#7SX(uu
oNa*|CSE>
public static void main(String[] args) & GM&,
{ vddh 2G
new TestMethod(); 8j%hxAV$
} "F8A:tR
} 8"2X 8C8
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