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)); D$7#&2y
} 78Du
for(int i=0;i<nEndPos.length-1;i++) Mc<u?H
{ & +*OV:[;
nEndPos = nStartPos[i+1]; X^Z!!KTH
} ![sXR
nEndPos[nEndPos.length-1] = nFileLength; wYg!H>5
} 6JDaZh"=K
} n_3R Q6
9}u,`&
Xjkg7p,HD@
//启动子线程 DY9]$h*y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; IvT><8<G
for(int i=0;i<nStartPos.length;i++) t&:L?K)j
{ [:FiA?O]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a&V;^ /
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), DU0/if9.
nStartPos,nEndPos,i); .] sJl
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^lAM /
fileSplitterFetch.start(); 8;V9%h`P>
} nYFrp)DLK
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), FY ms]bv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); I#&r5Q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ZZ7qSyBs?
nEndPos = " + nFileLength); M `^[Y2 c
// fileSplitterFetch[nPos.length-1].start(); i'7+ ?YL
u '7h(1@
IHYLM;@L
//等待子线程结束 dH!z<~
//int count = 0; An$2='=/
//是否结束while循环 >WIc"y.
boolean breakWhile = false; 'gvR?[!t
o87kF!x
%VH,(}i
while(!bStop) nuXL{tg6
{ =o~GLbsER
write_nPos(); sVK?sBs]
Utility.sleep(500); +a3E=GJ
breakWhile = true; > [J.
8 {V9)U
w y|^=#k
for(int i=0;i<nStartPos.length;i++) V`1,s~"q
{ 8HQ.MXKP
if(!fileSplitterFetch.bDownOver) TK fN`6
{ EU%,tp
breakWhile = false; ^>?=L\[
break; dPwyiV0
} kIVQ2hmv
} {d'-1z"q
if(breakWhile) pA~}_
break; >%k6k1CZ
k~^4
MQQm3VaKS
//count++; R7kkth
//if(count>4) `oJQA$UD
// siteStop(); m{/( 3
} %bAQ>E2;m
+cfEyiub
eF,F<IJT{
System.err.println("文件下载结束！"); MLu!8dgI
} d_,5;M^k
catch(Exception e){e.printStackTrace ();} ];OvV ,*
} gvA}s/
-2M~KlYl
S^eem_C
//获得文件长度 x9vSekV
public long getFileSize() x,!Dd
{ (?fU l$q\
int nFileLength = -1; <X:JMj+
try{ }l|S]m!
URL url = new URL(siteInfoBean.getSSiteURL()); 6OAs%QZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #$I@V4O;#
httpConnection.setRequestProperty("User-Agent","NetFox"); WVdV:vJ-
.|Huzk+
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int responseCode=httpConnection.getResponseCode(); ;!MQ@Fi^
if(responseCode>=400) %.Ma_4o Z
{ -B *W^-;*
processErrorCode(responseCode); C9!t&<\}
return -2; //-2 represent access is error > S>*JP
} q 84*5-
FH+X<
5To@d|{
String sHeader; Y~WdN<g
v Y0bK-
~5f&<,p!
for(int i=1;;i++) \8`7E1d
{ >>y`ap2%V
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); H<(F$7Q!\
//Utility.log(in.readLine()); 68Fl/
sHeader=httpConnection.getHeaderFieldKey(i); j uA@"SG
if(sHeader!=null) \c< oVF'
{ fF(2bVKP:
if(sHeader.equals("Content-Length")) ; oyV8P$
{ RbAl_xKI
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); eV[{c %wN:
break; @C)s4{V
} jE\G_>
} VJ~D.ec
else wJy]Vyd
break; C!j3@EZ$
} "do5@$p|
} 3iCe5VF
catch(IOException e){e.printStackTrace ();} 7q?ZieR
catch(Exception e){e.printStackTrace ();} rwRZGd *p
U.e!:f4{
--K)7
Utility.log(nFileLength); !l (Vk
T$5wH )<
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return nFileLength; 9>)b6)J D
} ^kKLi
9/k2zXY
>)kKP8l7
//保存下载信息（文件指针位置） V<QpC5
private void write_nPos() b^/u9
{ )|~&(+Q?]
try{ }r:"X<`
output = new DataOutputStream(new FileOutputStream(tmpFile)); |_;kQ(,
output.writeInt(nStartPos.length); >Xn,jMUW
for(int i=0;i<nStartPos.length;i++) (a[BvJf
{ @t%da^-HS"
// output.writeLong(nPos); .U!EA0B
output.writeLong(fileSplitterFetch.nStartPos); p<mL%3s0
output.writeLong(fileSplitterFetch.nEndPos); :Y99L)+=/
} &}"kF\
output.close(); $*C }iJsF
} d@ZDIy
catch(IOException e){e.printStackTrace ();} h4hAzFQ.s
catch(Exception e){e.printStackTrace ();} T3wTMbZ!VK
} :zHSy&i`
q"VmuQ
MhMiSsZ
//读取保存的下载信息（文件指针位置） o?baiOkH
private void read_nPos() .>"xp6
{ '12m4quO
try{ Hn/t'D3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); E`)e ;^
int nCount = input.readInt(); )s!A\a`vEd
nStartPos = new long[nCount]; ,U{dqw8E{
nEndPos = new long[nCount]; +^AdD8U
for(int i=0;i<nStartPos.length;i++) opfnIkCe
{ /TMVPnvz.
nStartPos = input.readLong(); 'V&g"Pb
nEndPos = input.readLong(); q[U pP`Z%
} v;(cJ,l
input.close(); V IzIl\<aM
} C*YQ{Mz(f
catch(IOException e){e.printStackTrace ();} T"g_a|7Tj
catch(Exception e){e.printStackTrace ();} [<@L`ki
} V^s, 3C
$_<[kci%
.x=abA$!9
private void processErrorCode(int nErrorCode) 1uo-?k
{ VzT*^PFBg
System.err.println("Error Code : " + nErrorCode); (Y~/9a4X
} 59.$;Ip;g
]3v)3Wp
u>'0Xo9R
//停止文件下载 +3))G
public void siteStop() ]xS%Er
{ ie1~QQ
bStop = true; WI1YP0V
for(int i=0;i<nStartPos.length;i++) WL+EpNKSf
fileSplitterFetch.splitterStop(); 4 $k{,
Id?-Og2iV
/Z2u0jNArP
} ) gl{ x
} ug%7}&
//负责部分文件的抓取 t]B`>SL3W
**FileSplitterFetch.java nAQ[ -NbW,
*/ c44s@E
package NetFox; #66i!}
Ku'a,\7z
(cVIjo+::
import java.io.*; }0&Fu?sP
import java.net.*; gbdzS6XW~
|E6Thvl$
KcT(/!
public class FileSplitterFetch extends Thread { -o/Vp>_UOE
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X!hzpg(`hR
String sURL; //File URL =sWK;`
long nStartPos; //File Snippet Start Position 'l<#;{
long nEndPos; //File Snippet End Position myo4`oH
int nThreadID; //Thread's ID nzbVI
boolean bDownOver = false; //Downing is over BD"Dzq
boolean bStop = false; //Stop identical +`flIG3RV
FileAccessI fileAccessI = null; //File Access interface remc_}`w
i6bUJtL
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Csu9u'.V
{ U/Cc!WXV]
this.sURL = sURL; dsX"S;`v
this.nStartPos = nStart; Lum=5zDo
this.nEndPos = nEnd; B/16EuH#
nThreadID = id; EwBrOq`C
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F*G]Na@6D
} c6b51)sQ"
X[/7vSqZ@w
hGKQK ^bn
public void run() b\\lEM>o1
{ n%WjU)<
while(nStartPos < nEndPos && !bStop) I?1BGaAA
{ blomB2vQ
ce$[H}rDB
*lDVV,T'}w
try{ eJf]"-
URL url = new URL(sURL); 8A0a/ 7Lj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }#<Rs
httpConnection.setRequestProperty("User-Agent","NetFox"); }se3y
String sProperty = "bytes="+nStartPos+"-"; |zRrGQYm
httpConnection.setRequestProperty("RANGE",sProperty); BuvnY
Utility.log(sProperty); ~"*W;|)
~APS_iG[
,OrrGwp&
InputStream input = httpConnection.getInputStream(); TQ![
//logResponseHead(httpConnection); Lt~&K$t7~
Eg&5tAyM
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byte[] b = new byte[1024]; I>8_gp\1
int nRead; D<70rBf2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) n"?*"Ya
{ ~|<'@B!6
nStartPos += fileAccessI.write(b,0,nRead); a?ete9Q+
//if(nThreadID == 1) T: My3&6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y ~-v0/
} "O# V/(
i\uj>;B
IT#Li
Utility.log("Thread " + nThreadID + " is over!"); bR}fj.gP
bDownOver = true; `s69p'<;p
//nPos = fileAccessI.write (b,0,nRead); k v_t6(qd
} {^Q,G x(
catch(Exception e){e.printStackTrace ();} ;mI^J=V3
} ,+d8
} O,7S1
ml2/}}
AP`1hz4].-
//打印回应的头信息 ~[F7M{LS
public void logResponseHead(HttpURLConnection con) K20Hh7cVJ
{ u-jV@Tz
for(int i=1;;i++) -F(luRBS(W
{ K#6@sas
String header=con.getHeaderFieldKey(i); "([gN:
if(header!=null) HP7~Zn)c
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0`V=x+*,
Utility.log(header+" : "+con.getHeaderField(header)); 0i5S=L`j
else $U/lm;{%
break; *"OlO}o
} *N: $,xf
} :^paI
qHheF%[\5
'cu14m_
public void splitterStop() oP T)vN?
{ ?x 0gI
bStop = true; $v_&jE
} n2_;:=
#%%!r$UL
|bQF.n_
} t>a D;|Y
Q(Yn8t
cDYOJu.
/* ]Ar,HaX-
**FileAccess.java RnC+]J+?4
*//文件访问(定位，写) GJ`._ju
package NetFox; -Ju;i<
import java.io.*; ukVBC"Ny
ue?3;BF 5
pyX:$j2R+%
public class FileAccessI implements Serializable{ B[h^]k
unqUs08
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -ON-0L
RandomAccessFile oSavedFile; i`<L#6RBT
long nPos; 4*o?2P$Q
IMM+g]#e
@d^DU5ats>
public FileAccessI() throws IOException RO3q!+a$/
{ |Vlx:
this("",0); G{,DoCM5WL
} pd`m//G
CAx eJ`Q
r9!s@n
public FileAccessI(String sName,long nPos) throws IOException 9Nna-}e?W
{ =z"8#_3A
oSavedFile = new RandomAccessFile(sName,"rw"); t_16icF9U
this.nPos = nPos; PJ&L7
oSavedFile.seek(nPos); $0OOH4
} &PApO{#Q
ai?N!RX%H
O#):*II`9
public synchronized int write(byte[] b,int nStart,int nLen) yJ]Va $M
{ .v}|Tp&k
int n = -1; {jwLVKT$
try{ x)N QRd
oSavedFile.write(b,nStart,nLen); VR1[-OE
n = nLen; z6;hFcO
} oC} u
catch(IOException e) q7_Ttjn-DV
{ A)j!Wgs^z
e.printStackTrace (); =vQ J2Rg
} lIx./Nf
KXl!VD,#`=
TF!v,cX
return n; p_]b=3wt~
} -F*vN'
~:0w%
oP4+:r)LKD
} <s\ZqL$f
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/* ^A=tk!C
**SiteInfoBean.java ^Z\"d#A
*/ .p o,.}
package NetFox; &Ruq8n<
mvTp,^1
Jd v;+HN[
public class SiteInfoBean { '3sySsD&O
$%'3w~h`
vGPsjxk&
private String sSiteURL; //Site's URL #639N9a~
private String sFilePath; //Saved File's Path ZQ*Us*9I
private String sFileName; //Saved File's Name ;PMh>ZE`
private int nSplitter; //Count of Splited Downloading File D*PEIsV
m__pQu:
l1O"hd'~s
public SiteInfoBean() uM,Ps}
{//nSplitter的缺省值为5 E,K>V:P*
//default value of nSplitter is 5 gX-hYQrC
this("","","",5); P,3w b
} b5 NlL`g
HOCj* O4
L@zhbWY
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E]m?R 4
{ aHYISjZ]>
sSiteURL= sURL; T*=*$%
sFilePath = sPath; U1lqg?KO
sFileName = sName; h9}*_qc&kV
this.nSplitter = nSpiltter; mW{>
W\w#}kY
4*E5@{D
} fn5-Tnsq*
nP*%N|0
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public String getSSiteURL() 1 JIU5u)
{ ?YS 3)
return sSiteURL; SA=>9L,2
} M3|G^q:l
dkCUU
5E~^-wX
public void setSSiteURL(String value) Xxd]j]
{ @@{5]Y
sSiteURL = value; o59$vX,
} XGC\6?L~
vDi Opd
<Up?w/9
public String getSFilePath() $7g+/3Fu^
{ f38e(Q];m
return sFilePath; 6'@{ * u
} x{<l8vL=-c
E!mv}
'x"(OdM:[
public void setSFilePath(String value) 2=0HQXXrq
{ 8=joVbs
sFilePath = value; udLIAV*
} 6j6;lNUc
fxr#T'i
{N/%%O.b
public String getSFileName() \#B<'J9.`
{ iQ2j ejd3(
return sFileName; qz (x
} 9`Fw}yAt
P#XV_2
*x;4::'Jn
public void setSFileName(String value) g; ]'
{ Ur>1eN%9'
sFileName = value; {)!>e
} 7X/t2Vih@
[?KGLUmTAI
5~:/%+F0=
public int getNSplitter() B,w ZI4oi*
{ Ox-eB
return nSplitter; emnT;kJ>
} Pn[oo_)s
-,p=;t#(
=D Q:0w
public void setNSplitter(int nCount) \y=oZk4
{ q^EY?;Y
nSplitter = nCount; DmLx"%H3
} |llJ%JhF
} _(kaaWJ
0.n[_?<(
flFdoEV.U)
/* d,JDfG)
**Utility.java @&WHX#
*/ Jut&J]{h
package NetFox; NzP71t+
tS]
y5m2u8+
public class Utility { l&qCgw
_"yA1D0d_
e}d(.H%l0
public Utility() uij^tN%
{ f6`GU$H
kv3Dn&<rJ
V<H9KA
} Op?"G
^sLx3a
//线程睡眠 "W(Ae="60
public static void sleep(int nSecond) +W*~=*h|
{ y@!o&,,mq
try{ g)#{<#*2
Thread.sleep(nSecond); G,|!&=Pe|E
} o1$u;}^|
catch(Exception e) 4<F z![>
{ &EQhk9j
e.printStackTrace (); LtMM89u
} }\7UU?@n
} ~!r;?38V`
NSB6 2
//日志 Kh(`6 f
public static void log(String sMsg) `/P/2{,~
{ Wa<<"x$
System.err.println(sMsg); &R_7]f+%)
} Q]xkDr?
\BXzmok
+C{-s
public static void log(int sMsg) Ytlzn%
{ )P:^A9&_n=
System.err.println(sMsg); ?";SUku
} ,=m.WmXE
} Jd>~gA}l
s51$x M
J @"#
/* +hmFFQQ}
**TestMethod.java @9gZH_ur>E
*/ g8%O^)d=>
package NetFox; &P|[YP37_
x [FLV8`b|
<s'de$[
public class TestMethod { !-f Bw
p?rlx#M
YS9RfK/
public TestMethod() YzI;)
{ ///xx/weblogic60b2_win.exe :;7I_tb
try{ r<e%;S
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b]+F/@h~]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y$r78h=4
SiteFileFetch fileFetch = new SiteFileFetch(bean); A]/o-S_
fileFetch.start(); { :tO RF
} J/?Nf2L4
catch(Exception e){e.printStackTrace ();} a[O6xA%
1q;v|F
Nujnm$!,Q
} =#b@7Yw:
c~Ka) dF|
7w/IHML
public static void main(String[] args) #dA$k+3
{ \WCQ>c?~
new TestMethod(); v~P,OP("c
} o|(5Sr&H
} Dsg>~J'
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