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)); @&M$oI$4*
} 0vm}[a4+i;
for(int i=0;i<nEndPos.length-1;i++) JqYt^,,Q:
{ vAp?Zl?g
nEndPos = nStartPos[i+1]; uA2-&smw
} ^L;k
nEndPos[nEndPos.length-1] = nFileLength; Q.Ljz Z
} &SE+7HXw
} 5!)_"u3
!2Q>
b5Pakz=jNM
//启动子线程 mMRdnf!Uid
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /*yPy?
for(int i=0;i<nStartPos.length;i++) a2N4Jg@
{ 4\%XC F!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mrz@Y0mgL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ngHPOI16
nStartPos,nEndPos,i); LQrm/)4bF5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ghpk0ia%d
fileSplitterFetch.start(); eEG]JH
} [r5k8TB1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Jz6,2,LN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); '}q1 F<&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &k2nt
nEndPos = " + nFileLength); znl_~:.4]X
// fileSplitterFetch[nPos.length-1].start(); Tx'ctd#Y
>ey-j\_v
!,3U_!
//等待子线程结束 ^ M4-O~
//int count = 0; ~ U,a?LR/
//是否结束while循环 kwd)5J
boolean breakWhile = false; X@n\~[.B
AE"E($S`
vz_ZXy9Z
while(!bStop) HGjGV]N5
{ #Qp.O@e
write_nPos(); SZm)`r\A
Utility.sleep(500); W=k%aB?p
breakWhile = true; K2GcU_*t
H^no&$2`1
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for(int i=0;i<nStartPos.length;i++) !bi}9w
{ 9k@`{+wmZ
if(!fileSplitterFetch.bDownOver) X519} l3
{ Qb;5:U/x
breakWhile = false; SAEV "
break; 32sb$|eQq
} $q6'VLPo
} s*B-|
if(breakWhile) }@V,v[&e
break; dn1Tu6f;|
pH1 9"=p<
HjFY>(e
//count++; Hf'yRKACj
//if(count>4) @Sl!p)
// siteStop(); j>0~"A
} 9#;UQ.qA
igW>C2J
3[jk}2R';p
System.err.println("文件下载结束！"); ^:RDu q
} Nh[{B{k
catch(Exception e){e.printStackTrace ();} Q4;br?2H
} RO"*&o'K'
HGgw<Os-k
\O7?!i
//获得文件长度 Tcglt>tj"
public long getFileSize() [[[QBplJ
{ {:3XP<hqN
int nFileLength = -1; (Rc0l;
try{ U "qO&;m
URL url = new URL(siteInfoBean.getSSiteURL()); ]PnE%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~"*;lT5KX
httpConnection.setRequestProperty("User-Agent","NetFox"); B43o_H|s
r]=3aebR.
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int responseCode=httpConnection.getResponseCode(); Vo%UiVHy
if(responseCode>=400) diLjUC`69
{ D^Z~>D6
processErrorCode(responseCode); A_t<SG5
return -2; //-2 represent access is error O;A/(lPW+
} Hf/2KYZ
lE54RX}e4
KcB?[
String sHeader; T'*.LpNP,
o^Y'e+T"
YSuwV)Y
for(int i=1;;i++) (8r?'H8ZO
{ IpxFME%!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Q#bFW?>y,
//Utility.log(in.readLine()); )W@H
sHeader=httpConnection.getHeaderFieldKey(i); ^saJfr x
if(sHeader!=null) 5m+:GiI
{ g"3h#SMb
if(sHeader.equals("Content-Length")) , "zS pN
{ uREc9z`Q'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~P5!VNJ;r
break; Ej1 [ry
} Dz&4za+{
} b)u9#%Q
else ``kKi3TWJ
break; r)mm8MI!Z
} qR_"aQ7s2
} UY**3MK
catch(IOException e){e.printStackTrace ();} ZUyM:$
catch(Exception e){e.printStackTrace ();} zYOPE 6E
n20H{TA
jkNZv. )p
Utility.log(nFileLength); WII_s|YSt%
$Mx.8FC +
kmW!0hm;e
return nFileLength; lb1(1|#
} pAmTwe
U gB
B`hxF(_p/
//保存下载信息（文件指针位置） LFSOHJj
private void write_nPos() su=.4JcK
{ xuelo0h,
try{ sZ'3PNpCP
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?NI)3-l
output.writeInt(nStartPos.length); %!rsu-W:Y
for(int i=0;i<nStartPos.length;i++) ,XP9NHE
{ i=2+1;K
// output.writeLong(nPos); UsQv!Cwu^
output.writeLong(fileSplitterFetch.nStartPos); 2$NP46z}
output.writeLong(fileSplitterFetch.nEndPos); RpLm'~N'
} O!f*@
output.close(); McnP>n
} XB;;OP12
catch(IOException e){e.printStackTrace ();} 4r(rWlM
catch(Exception e){e.printStackTrace ();} ]Ly)%a32
} 'd?8OV
oS_p/$F,
<R{\pz2w
//读取保存的下载信息（文件指针位置） Y,mH ]
private void read_nPos() sCb?TyN'n
{ "<O?KO3K
try{ ~[9 ]M)=O0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); dy`~%lX?
int nCount = input.readInt(); 1xtbhk]D
nStartPos = new long[nCount]; gdC=SFb b
nEndPos = new long[nCount]; )QZ?Bf
for(int i=0;i<nStartPos.length;i++) 6ldDt?iSg
{ C1G Wi4)
nStartPos = input.readLong(); SwP h-6
nEndPos = input.readLong(); y6jTT%
} %n}]$ d
input.close(); cRg$~rYd
} nj9hRiLn
catch(IOException e){e.printStackTrace ();} {{DW P-v4
catch(Exception e){e.printStackTrace ();} oW+R:2I~O
} FySK&
98O z
U3U eTa_
private void processErrorCode(int nErrorCode) x@k9]6/zs
{ b`:Eo+p
System.err.println("Error Code : " + nErrorCode); L7xTAFe
} !E7/:t4
Ta[}k/zW
@/7Rp8Fr
//停止文件下载 g*]<]%Py"
public void siteStop() vRY4N{v(<
{ ,zw
bStop = true; 0^[$0]Mt[
for(int i=0;i<nStartPos.length;i++) fg1 zT~
fileSplitterFetch.splitterStop(); =q"3a9pb7
Ahebr{u
uC;@Yi8
} ss2:8up 99
} 6% ,Q
//负责部分文件的抓取 9SFiL#1
**FileSplitterFetch.java %Bo Jt-v
*/ ):[[Ch_
package NetFox; $Y4 Ao-@
TMRXl.1
G![1+2p:Tq
import java.io.*; l;;:3:
import java.net.*; W.CIyGK
>3Y&jsh<
(p2a{v}fEz
public class FileSplitterFetch extends Thread { w\QpQ~OX
g+CHF?O
rj5:YQEH;
String sURL; //File URL <=`@`rm{
long nStartPos; //File Snippet Start Position F%|(pHk
long nEndPos; //File Snippet End Position kR_[p._
int nThreadID; //Thread's ID C'$U1%: j
boolean bDownOver = false; //Downing is over CRf^6k_;(
boolean bStop = false; //Stop identical Cv=0&S.
FileAccessI fileAccessI = null; //File Access interface lubS{3<
7)]G"m{
w5nRgdboy!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException GS^4tmc
{ RcE%?2lD
this.sURL = sURL; ]zm6;/S
this.nStartPos = nStart; ~>EVI=?
this.nEndPos = nEnd; >]`x~cE.5
nThreadID = id; C^~iz in
fileAccessI = new FileAccessI(sName,nStartPos);//定位 BxG;vS3>*e
} ](ninSX1w
k{#:O=
bC{~/ JP
public void run() ?:2Xh/8-
{ cP Y^Bf5)
while(nStartPos < nEndPos && !bStop) v;A
{ I[|I\tW
["7}u^z@<+
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try{ Tv KX8m"
URL url = new URL(sURL); aG ,uF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); - t+Mh.
httpConnection.setRequestProperty("User-Agent","NetFox"); 'F~u \m=E
String sProperty = "bytes="+nStartPos+"-"; g?`J,*y
httpConnection.setRequestProperty("RANGE",sProperty); I F@M
Utility.log(sProperty); *Zvw&y*
R}]FIu
c2U>89LlZ
InputStream input = httpConnection.getInputStream(); I@B7uFj
//logResponseHead(httpConnection); bM'AD[
p)ONw"sb
~DD/\V
byte[] b = new byte[1024]; nZ*P:K t:
int nRead; nGt8u4gcP
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) MoA{ /{
{ g,;MV7yE
nStartPos += fileAccessI.write(b,0,nRead); 7MfT~v
//if(nThreadID == 1) tX_eN
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (!b: gG
} c'6H@m#=
8+u8piG
|bk*Lgkzw
Utility.log("Thread " + nThreadID + " is over!"); s5pY)6)
bDownOver = true; TQou.'+v
//nPos = fileAccessI.write (b,0,nRead); xI@~Ig
} d.Z]R&X08
catch(Exception e){e.printStackTrace ();} xv:?n^yt.[
} jBC9Vt;B
} A>?fbY2n
oxzNV&D[{`
7I|%GA_
//打印回应的头信息 gU?)
public void logResponseHead(HttpURLConnection con) x6t;=
{ |^F-.Z
for(int i=1;;i++) eZ!k'bS=
{ qkIU>b,B
String header=con.getHeaderFieldKey(i); $o/>wgQY-
if(header!=null) @2mP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9ZBF1sMg
Utility.log(header+" : "+con.getHeaderField(header)); [a3 0iE
else "jHN#}
break; CytpL`&^]
} pR"qPSv'
} "|.(yN
Bag#An1
C gx?K]>y
public void splitterStop() - -G1H
{ k mjm6
bStop = true; B /W$RcV
} E(@;p%:
FMVmH!E
oo!g?X[[
} ~laZ(Bma);
asg>TOW
o >Lk`\
/* Pio^5jhB6
**FileAccess.java z+*Z<c5d
*//文件访问(定位，写) -?W@-*J
package NetFox; |6>_L6t
import java.io.*; 9zJ`;1
%\l,X{X
L?0l1P
public class FileAccessI implements Serializable{ qj&)w9RLJE
jO55<s94
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 mV,R0olF
RandomAccessFile oSavedFile; ^aXBt
long nPos; ZhsZywM
"b 0cj
h6*`V
public FileAccessI() throws IOException U3}R^W~eb
{ _ ^{Ep/ME=
this("",0); ]D%k)<YK
} N-gRfra+8L
6<Z:Xw
[fp"MPP3
public FileAccessI(String sName,long nPos) throws IOException blcKtrYg
{ vgj^-
oSavedFile = new RandomAccessFile(sName,"rw"); O@iW?9C+
this.nPos = nPos; Gq*)]X{Ua
oSavedFile.seek(nPos); E0Q"qEvU
} R(sM(x5a`
0?SLRz8
Jdn*?hc+
public synchronized int write(byte[] b,int nStart,int nLen) d 4]%Wdvf
{ BuTIJb+Q\
int n = -1; H|UL5<:]D
try{ %z~U@Mka
oSavedFile.write(b,nStart,nLen); ^d80\PXz
n = nLen; :eW~nI.Vc
} hli10p$
catch(IOException e) !dY:S';~
{ bZ.N7X PH
e.printStackTrace (); 6>:~?gs
} d|]O<]CG_
zXZ'nJ5OGG
[+g@@\X4
return n; wkD:i2E7
} (0W}e(D8
jJZsBOW[8
y.p6%E_`
} fm%RNAPvc
7Zt\G-QV
gvNZrp>e!
/* `{F~'t['
**SiteInfoBean.java R*Z]
*/ |xZcT4
package NetFox; mE`qvavP|/
>&QH{!(
{X<4wxeTo
public class SiteInfoBean { xn@0pL3B~
*ldMr{s<R
U5!f++
private String sSiteURL; //Site's URL q9Sz7_K
private String sFilePath; //Saved File's Path -Zg @D(pF
private String sFileName; //Saved File's Name Reu{
private int nSplitter; //Count of Splited Downloading File *Ca)RgM
9K':Fn2,
lt6;*z[
public SiteInfoBean() UZP6x2:=
{//nSplitter的缺省值为5 _i[)$EgFm
//default value of nSplitter is 5 2BDan^:-Av
this("","","",5); Wi[m`#
} -I-Uh{)j
*3O>J"
MJ,ZXJXs
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) xs!g{~V{
{ 1Xr"h:U_X
sSiteURL= sURL; u\R`IZ&O
sFilePath = sPath; QZ3(u<f
sFileName = sName; HDVl5X`j'
this.nSplitter = nSpiltter; fu<2t$Cn>
`E5"Pmg
P5>5ps"iU
} u=;nU(]M '
!?o$-+a|
^YR|WKY
public String getSSiteURL() oD#>8Aws
{ 7sc<dM
return sSiteURL; R pI<]1
} ncattp
/%YiZ#
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public void setSSiteURL(String value) RO{@RhnV
{ iv:/g|MBI&
sSiteURL = value; /J.\p/%\
} 6lmiMU&V
F`0c?)
ge):<k_
public String getSFilePath() =+`j?1
{ #)0Tt>d6
return sFilePath; y168K[p
} -,Q$
b"nG-0JR
(X(1kj3
public void setSFilePath(String value) T5Sg2a1&
{ dHG Io
sFilePath = value; 8b:clvh
} &.Latx
Ji6`-~ k
P$18Xno{
public String getSFileName() :%#r.p"6x
{ :vK(LU0K
return sFileName; NdsX*o@a
} ?orhJS
vZE|Z[M+<
9G#8%[W
public void setSFileName(String value) b>QM~mq3^I
{ tyuk{*Me:
sFileName = value; 3gG+`{<
} - LiPHHX<
LMFK3Gd[
>H}jR[H'
public int getNSplitter() Ty3CBR{6
{ .3a:n\tY
return nSplitter; .6#cDrK
} /z1p/RiX
`M?v!]o
e)HhnN@
public void setNSplitter(int nCount) 1t~FW-:
{ Y .
nSplitter = nCount; dXiE.Si
} 1xO!w+J#
} sK@Y!oF}\
T+;H#&
*#lBQBH|.
/* 3J'73)y
**Utility.java LAv:+o(m/
*/ "Su b4F`
package NetFox; 4<T*i{[
*%X6F~h(u
vZb|!#I
public class Utility { -c+[6A>j
>-5td=:Z
.!yWF?T8
public Utility() X-kXg)!Bg
{ ]6{(Hjt
qGnPnQc
By?nd)
} -RG8<bI,
P>*Fj4Z~
//线程睡眠 }+Rgx@XZ\
public static void sleep(int nSecond) s, n^
{ EkJVFHfh
try{ *wC\w
Thread.sleep(nSecond); /"""z=q
} ]}z'X!v_@
catch(Exception e) I %|@3=Yc
{ %cH8;5U40
e.printStackTrace (); , Aq9fyC%
} ^IX%dzM
} _1>SG2h{fV
`d7gm;ykp
//日志 @B,j;2eb
public static void log(String sMsg) o'C~~Vg).
{ t=n+3`g
System.err.println(sMsg); ud0QZ X
} tJ=3'?T_k
(M ]XNn
Dv<wge`
public static void log(int sMsg) AL>c:K)qO
{ -$+,]t^GV
System.err.println(sMsg); j4;Du>obQ
} i@P9EU
} <7=&DpjI7F
TC qkm^xv
O(VxMO
/* }@Xh xZu
**TestMethod.java +J|+es
*/ i[$-_
package NetFox; .#*D!;f
pw@`}cM=
]\A1mw-T
public class TestMethod { w#*/y?"D
m8'@UzB
bb|}'
public TestMethod() w6vLNX
{ ///xx/weblogic60b2_win.exe fO K|:
try{ sffhPX\I
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -i#J[>=w{C
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @-0Fe9 n=
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9khjwt
fileFetch.start(); {!L=u/qs"
} vR7ctav
catch(Exception e){e.printStackTrace ();} =0,|/1~
]?[zx'|
2(pLxVl
} ^^%JoQ.
/K7Bae5h
M~uMY+>
public static void main(String[] args) tKwn~T
{ J*5hf:?i
new TestMethod(); 14mf}"z\
} Q4RpK(N
} Nepi|{
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