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)); cUDgM
} !@ YXZ
for(int i=0;i<nEndPos.length-1;i++) WO,xMfK
{ [ev-^[
nEndPos = nStartPos[i+1]; u>Ki$xP1
} ZZ)G5ji
nEndPos[nEndPos.length-1] = nFileLength; swpnuuC-
} "L2m-e6
} :a<hQ|p
}IlP:
g3?U#7i
//启动子线程 hQgN9S5P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; S9Yt1qb
for(int i=0;i<nStartPos.length;i++) 3#<*k>1G?
{ %>XN%t'6aT
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), | D.C!/69
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P?3{z="LzJ
nStartPos,nEndPos,i); 77:'I
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wh~sZ
fileSplitterFetch.start(); uf@U:V
} O=jN&<rb
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DPJh5d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MPRO !45Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3^G96]E
nEndPos = " + nFileLength); mT_GrIl[
// fileSplitterFetch[nPos.length-1].start(); g<[rH%\6fg
dA#{Cn;
F1A1@{8bN
//等待子线程结束 v29G:YQe
//int count = 0; "~p+0Xws9
//是否结束while循环 G+Dpma ]
boolean breakWhile = false; ZcZ;$*
j.QHkI1.
z*.v_Mx
while(!bStop) -WT3)On
{ e!o(g&wBj
write_nPos(); TvrwVL)
Utility.sleep(500); Gidkt;lj
breakWhile = true; ~|) 9RUXr>
4S *,\q]q
!z=pP$81
for(int i=0;i<nStartPos.length;i++) d]M[C[TOX
{ 2X@G"
if(!fileSplitterFetch.bDownOver) } 21j
{ .u< U:*
breakWhile = false; '>^Xqn
break; ( D}"&2
} |@`"F5@,
} *:arva5
if(breakWhile) 6f}e+80
break; 3%M.U)|+
E8tD)=1
+?e}<#vd'?
//count++; 4 10:%WGc
//if(count>4) OKQLv+q5K)
// siteStop(); 5V|tXsy:
} POBpJg
_ +KmNfR
glor+
System.err.println("文件下载结束！"); B/Ba5z"r$
} #Si|!
catch(Exception e){e.printStackTrace ();} 3Hm7 uBZ
} q 22/_nSC
%}F"*.
zPQ$\$7xB
//获得文件长度 W#45a.v
public long getFileSize() 6`"ZsO
{ j<$R4A1
int nFileLength = -1; f8!l7{2%q
try{ sfC@*Y2XT
URL url = new URL(siteInfoBean.getSSiteURL()); +{xG<Wkltz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FT_k^CC
httpConnection.setRequestProperty("User-Agent","NetFox"); b]dxlj} <
s, -*q}
|+/$ g.
int responseCode=httpConnection.getResponseCode(); eG^z*`**
if(responseCode>=400) 0Uaem
{ $SF3odpt
processErrorCode(responseCode); Th+|*=Il
return -2; //-2 represent access is error hgj0tIi/
} s=\7)n=,M
em/Xu
mCrU//G
String sHeader; {Pvr??"r
Isp_U5M
3YRBI|XO
for(int i=1;;i++) ;@'0T4Z&l
{ P6E1^$e
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); auA.6DQ
//Utility.log(in.readLine()); n +dJc
sHeader=httpConnection.getHeaderFieldKey(i); *cy.*@d
if(sHeader!=null) 2?H@$-x>
{ ,^!Zm^4,
if(sHeader.equals("Content-Length")) GFY-IC+fc
{ Deog4Ol"/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K*[0dza$
break; "DzGBu\
} *e,CDV
} intvlki]be
else S r[IoF)
break; m^c%]5$
} @6[x%j/!bt
} %8g$T6E[<2
catch(IOException e){e.printStackTrace ();} TwwIt5_fN
catch(Exception e){e.printStackTrace ();} ,iohfZz
w=gQ3j#s
{z-NlH
Utility.log(nFileLength); yvS^2+jW
+%x^RV}
ZG!x$yi$
return nFileLength; R$v i!0
} _=)!xnYf
;,FT&|3o
O<Jwaap
//保存下载信息（文件指针位置） i$g|?g~]
private void write_nPos() Mf#2.TR
{ a'm!M:w
try{ Age-AJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); - =yTAx
output.writeInt(nStartPos.length); wiKCr/
for(int i=0;i<nStartPos.length;i++) .M}06,-
{ ]zX\8eHp!
// output.writeLong(nPos); D@2Ya/c
output.writeLong(fileSplitterFetch.nStartPos); ^CO#QnB @
output.writeLong(fileSplitterFetch.nEndPos); kaV%0Of]
} }t}38%1i
output.close(); M2a}x+5'
} dzpj9[
catch(IOException e){e.printStackTrace ();} ~igRg~k:/
catch(Exception e){e.printStackTrace ();} _J+]SNk
} il=?of\,i
'/n\Tg+
Xk 5oybDI
//读取保存的下载信息（文件指针位置） @_G` Ok4
private void read_nPos() rK*hTjVn
{ m]E o(P4+
try{ ,&-S?|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); BllDWKb
int nCount = input.readInt(); <r@bNx@T
nStartPos = new long[nCount]; mMn2(
nEndPos = new long[nCount]; I4A;
for(int i=0;i<nStartPos.length;i++) Cl%V^xTb
{ cF-Jc}h
nStartPos = input.readLong(); tbL1g{Dz,
nEndPos = input.readLong(); R %Rv
} BYTXAZLb
input.close(); S6=\r{V
} =mDy@%yx!
catch(IOException e){e.printStackTrace ();} %{7$\|;J'
catch(Exception e){e.printStackTrace ();} Qf/j:
} tzx:*
Rs`Vr_?Hk
+>n.T
private void processErrorCode(int nErrorCode) k*A4;Bm
{ k?!TjBKm
System.err.println("Error Code : " + nErrorCode); kO /~i
} H0 {Mlu9
aY3pvOV
s{b0#[
//停止文件下载 O8!!UA8V
public void siteStop() l#mqV@?A~
{ JDIz28Ww
bStop = true; VGq{y{(
for(int i=0;i<nStartPos.length;i++) zS&7[:IRs'
fileSplitterFetch.splitterStop(); =>E44v
2 rbX8Y
[YL sEo=
} WBIQ%XB'
} (, ;MC/l
//负责部分文件的抓取 Pcdi
**FileSplitterFetch.java 11nO<WH
*/ KFCQYdI`d
package NetFox; wWp?HDl"M
tyBg7dP
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import java.io.*; a,en8+r]
import java.net.*; #c8"
C?_t8G./_
&utS\-;G
public class FileSplitterFetch extends Thread { @]}Qh;a~
3hp tP
P}w^9=;S
String sURL; //File URL !XG/,)A
long nStartPos; //File Snippet Start Position o(S^1j5
long nEndPos; //File Snippet End Position zIX}[l4EW~
int nThreadID; //Thread's ID 0B#rqTEKu
boolean bDownOver = false; //Downing is over (7 ]\p
boolean bStop = false; //Stop identical {Tjtj@-
FileAccessI fileAccessI = null; //File Access interface *X"F:7
^MF=,U'8
>?:i6&4o
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oW\Q>c7 =
{ rzc 3k~@
this.sURL = sURL; % B7?l
this.nStartPos = nStart; _.s\qQ
this.nEndPos = nEnd; 72BzvY.
nThreadID = id; +4p2KYO
fileAccessI = new FileAccessI(sName,nStartPos);//定位 b*$o[wO9
} .pNq-T
&**.naSo
i&AXPq>`
public void run() Rqv+N]
{ 'PxL^
while(nStartPos < nEndPos && !bStop) 3l41r[\
{ j:\_*f
7ZR0M&pX
/eI,]CB'z
try{ \f<thd*bC
URL url = new URL(sURL); '<U[;H9\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0(.R?1*:Rf
httpConnection.setRequestProperty("User-Agent","NetFox"); .5$V7t.t$\
String sProperty = "bytes="+nStartPos+"-"; )Uoe~\
httpConnection.setRequestProperty("RANGE",sProperty); >u%[J!Y;;
Utility.log(sProperty); ' ]H#0.
:7'0:'0$t
j+ T\c2d
InputStream input = httpConnection.getInputStream(); T!O3(
//logResponseHead(httpConnection); cmC&s'/8`D
TO;]9`~;Mu
0[3tW[j
byte[] b = new byte[1024]; Hr_x~n=w
int nRead; ~>wq;T:=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) '!2
{ 'j=PbA
nStartPos += fileAccessI.write(b,0,nRead); 4'u|L&ow
//if(nThreadID == 1) 0v,`P4_k
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YH:W]
} r>D[5B
U7Sl@-#|
%.r5E2'
Utility.log("Thread " + nThreadID + " is over!"); DrYoC7
bDownOver = true; 9Y*VzQE
//nPos = fileAccessI.write (b,0,nRead); <=LsloI
} 8~XI7g'5x
catch(Exception e){e.printStackTrace ();} ,YuWz$aF{
} +HVG5l
} wNlV_
'e8d["N
(Nve5
//打印回应的头信息 E].a|4sh
public void logResponseHead(HttpURLConnection con) IcNIuv
{ l.LFlwt
for(int i=1;;i++) !&:.Uh
{ A'P}mrY
String header=con.getHeaderFieldKey(i); j^R~ Lt4
if(header!=null) W(3~F2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); e?'k[ES^
Utility.log(header+" : "+con.getHeaderField(header)); .LVOaxT
else -2mOgv
break; F$pd]F!#
} aABE= 9Y
} x[h<3V"
?}>B4Z)
x[,wJzp\6
public void splitterStop() H'(o}cn7~
{ 8`R}L
bStop = true; bKbpI>;[
} d%|#m)
!D]6Cq
'}[L sU
} c^/?VmCQ}
nV6g]#~@
g960;waz3
/* ;|e 0{Jrz
**FileAccess.java I<o4l[--
*//文件访问(定位，写) ~+NFWNgN
package NetFox; \|4MU"ri
import java.io.*; .J! $,O@
Q $,kB<M
j~<iTLM
public class FileAccessI implements Serializable{ 4)S?Y"Bs
x>/@Z6Wxz
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 nJ`a1L{N
RandomAccessFile oSavedFile; Yka yT0!
long nPos; <EE+ S#z
4%.2=
yeh adm\
public FileAccessI() throws IOException Z.#glmw^=R
{ G"R>aw
this("",0); `x^,k% :4
} 6xQe!d3>s3
fP4IOlHkE
t 1'or
public FileAccessI(String sName,long nPos) throws IOException $@!&ML
{ ?^A:~"~
oSavedFile = new RandomAccessFile(sName,"rw"); ,lGwW8$R
this.nPos = nPos; ?;kc%Rz
oSavedFile.seek(nPos); =kkA
} 0BZOr-i
~5?n&pF
D&lXi~Z%.
public synchronized int write(byte[] b,int nStart,int nLen) -D':7!@
{ 9fLP&v
int n = -1; h 7P?n.K
try{ +as\>"Cj+2
oSavedFile.write(b,nStart,nLen); V$%Fs{
n = nLen; D,R2wNF
} Hu!>RSg,,2
catch(IOException e) 7)X&fV6<8
{ Q`fA)6U
e.printStackTrace (); Bc,z]
} !6`nN1A
dK`O,[}
?26[%%
return n; 3cQmxp2*
} EJ|ZZYke!
!ZcALtq
Cjb p-
} !ef)Ra-W
M L_J<|,J
;SP3nU))
/* ZQ8Aak
**SiteInfoBean.java Y2$`o4*3
*/ 5rSth.&
package NetFox; 0-O.*Q^
2xxwQwg8
\O4=mJ
public class SiteInfoBean { s,q!(\{Pv
{oC69n:
K#yH\fn8
private String sSiteURL; //Site's URL R')GQ.yYq
private String sFilePath; //Saved File's Path T$B4DQ
private String sFileName; //Saved File's Name ~x\Q\Cxp
private int nSplitter; //Count of Splited Downloading File @WE$%dr
mM%BO(X{=
K\r=MkA.>
public SiteInfoBean() g9Qxf%}
{//nSplitter的缺省值为5 nUu|}11(
//default value of nSplitter is 5 , |B\[0p
this("","","",5); 7oSuLo=
} ?2/M W27w
Bd[}A9O[
$f\-.7OD
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c>k6i?u:X7
{ L(rjjkH
sSiteURL= sURL; |n%N'-el
sFilePath = sPath; )[Cm*Xxa$
sFileName = sName; $e\R5Lu
this.nSplitter = nSpiltter; :G)x+0u
4s2ex{$+MA
hkc_>F]Hx
} aB_z4dqwU
'hWRwP|
D1/$pA+B
public String getSSiteURL() =jHy6)6w
{ NP/2gjp
return sSiteURL; 51usiOq
} gQGiph |
eT?LMBn\
+t6m>IBu
public void setSSiteURL(String value) t,YAk ?}
{ )&-+:u0
sSiteURL = value; ;sJ2K"c
} <C xet~x
W%:zvqg v
f>PU# D@B
public String getSFilePath() 7 {<lH%Tn
{ ]d(}b>gR~(
return sFilePath; $SgD| 9
} p.olXP
:.^rWCL2
2%H(a)
public void setSFilePath(String value) #$QY[rf=6
{ J'v|^`bE
sFilePath = value; 3E9j%sYk
} CAO{$<M5m
MQu6Tm H
vnpX-c
public String getSFileName() /y@iaptC
{ ,B!Qv3bn
return sFileName; Ss}0.5Bq
} b@Cvs4
^5F/=TtE G
i>}z$'X
public void setSFileName(String value) )I9(WVx!]
{ }(6k7{,Gw,
sFileName = value; mer{Jys
} Rl8-a8j$f.
Pl>t\`1:|A
:Tl?yGF
public int getNSplitter() N<WFe5
{ tDVdl^#
return nSplitter; Uk4">]oct
} 8&bj7w,K
#U6qM(J
mYvm_t9
public void setNSplitter(int nCount) <hdCO< 0(
{ `$HO`d@0*R
nSplitter = nCount; %cL:*D4oz
} TMBdneS-s
} I&c#U+-A'
on$a]zx'@
l|{<!7a
/* v2Y=vr
**Utility.java ){~.jP=-#
*/ 1g+<`1=KT
package NetFox; Yn/-m Z
1F/&Y}X
@So"(^
public class Utility { ~sD'pS
/jAs`"U
T~Cd=s(T"
public Utility() ' r/1+.
{ WDq3K/7\
ua-p^X`w
y C#{nUdw
} 511q\w M
Heu@{t.[!D
//线程睡眠 xh$[E&2u
public static void sleep(int nSecond) b;vO`
{ l(W3|W#P
try{ i^(<E0vS
Thread.sleep(nSecond); oZCO$a
} HYS7=[hv6
catch(Exception e) DQd&:J@?
{ 8*X8U:.0o
e.printStackTrace (); K"61i:F
} q!4dK4`#5
} Wu(GC]lTG
6gXc-}dp
//日志 e9hQJ 1{)x
public static void log(String sMsg) s#ykD{Z
{ p*Cbe\
System.err.println(sMsg); U<x3=P
} RD^o&VXO
2#!D"F
3h&s=e!
public static void log(int sMsg) Z)<>d.
{ <_~`)t
System.err.println(sMsg); cl:YN]BK
} x8[8z^BV?e
} QXCI+Fcg
SL*(ZEn"
UT-=5
/* +?8nY.~,'
**TestMethod.java |8"HTBb\CW
*/ ofJ@\xS
package NetFox; J7H1<\=cJb
ZyG528O22
wC19
public class TestMethod { 3c)LBM
_z;N|Xe
W$W7U|Z9y+
public TestMethod() tF4"28"h
{ ///xx/weblogic60b2_win.exe z|Xl%8
try{ LS`Gg7]S
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?^5x d1>E
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <q|19fH-5
SiteFileFetch fileFetch = new SiteFileFetch(bean); :3k(=^%G!
fileFetch.start(); JW$#~"@r
} BmZd,}{
catch(Exception e){e.printStackTrace ();} <M=K!k
$d'Gh2IGA
<_+8c{G
} BN=,>-O%
iH2|w
{pqm&PB04
public static void main(String[] args) 8r5j~Df
{ WE3l*7<@
new TestMethod(); <H.Ml>q:r
} Z1&8U=pax
} \6o ~ i
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