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)); ]6M,s0
} @yo6w}3+-
for(int i=0;i<nEndPos.length-1;i++) @<`V q
{ rVP{ ^Jdo
nEndPos = nStartPos[i+1]; Qj|rNeM_
} 3!$+N\ #w
nEndPos[nEndPos.length-1] = nFileLength; =fJU+N+<
} &,yF{9$G
} h3-^RE5\`S
-+Ot'^
OF03]2j7<|
//启动子线程 }xBDyr63
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bN7m[GRO.
for(int i=0;i<nStartPos.length;i++) A*~G[KC3(
{ (Gw*xsn1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TgaxZW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), .$7RF!p
nStartPos,nEndPos,i); K_~kL0=4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a"Xh
fileSplitterFetch.start(); r-go921
} CAC%lp
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `+rwx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5:jme$BI
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Arm'0)B>
nEndPos = " + nFileLength); kJpO0k9?eY
// fileSplitterFetch[nPos.length-1].start(); TY'c'u,
[T,Hpt
(xHu@l!]
//等待子线程结束 i1XRBC9
//int count = 0; AO>b\,0Me
//是否结束while循环 U[02$gd0l
boolean breakWhile = false; DxwR&S{
1ANFhl(l
}dpTR9j=
while(!bStop) !y B4;f$
{ K4jHha
write_nPos(); &a=78Z
Utility.sleep(500); 1G7l+6w5~^
breakWhile = true; "[!b5f3!I
'tY(&&
+<.o,3
for(int i=0;i<nStartPos.length;i++) EQ ee5}
{ qB (Pqv
if(!fileSplitterFetch.bDownOver) #>("(euXMF
{ LWm1j:0
breakWhile = false; bm 4RRI
break; Y!_{:2H8p
} IdN3Ea]
} / Ws>;0
if(breakWhile) mvK^')
break; y: x<`E=
Ak,JPzT
a#"orc j
//count++; '~Cn+xf4]
//if(count>4) rR :ZTfJs"
// siteStop(); tT>LOI_z
} Jw8?o/1D@
}x\#ul)
`-.2Z 0
System.err.println("文件下载结束！"); pB\:.?.pd
} r dSL
catch(Exception e){e.printStackTrace ();} 8-NycG&)
} ~abyjM
X!K>.r_Dg
`(h^z>%
//获得文件长度 bsDA&~)s
public long getFileSize() ;b*qunJ3L
{ fs 2MYat
int nFileLength = -1; l=p_
try{ 5{k,/Z[L
URL url = new URL(siteInfoBean.getSSiteURL()); iuGwc086
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x<M::")5!V
httpConnection.setRequestProperty("User-Agent","NetFox"); wpuK?fP
aqN{@|
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int responseCode=httpConnection.getResponseCode(); bf0,3~G,P
if(responseCode>=400) o+&Om~W
{ T>'O[=UWh
processErrorCode(responseCode); ,wes*
return -2; //-2 represent access is error #55:qc>m
} <O 0Q]`i
Rlk3AWl2u
V%s7*`U
String sHeader; )f|`mM4DW!
j!>P7 8
OyVP_Yx,V
for(int i=1;;i++) Q;8z&4s@
{ $uDgBZA\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Qgj# k
//Utility.log(in.readLine()); 6vsA8u(|V#
sHeader=httpConnection.getHeaderFieldKey(i); eZAMV/]jH
if(sHeader!=null) #| _VN %!
{ 'Og@<~/Xy
if(sHeader.equals("Content-Length")) ?&#LmeZ}K
{ Bh2l3J4X
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); p"p~Bx
break; [oVM9Q
} &L$9Ii
} ZI!:
else >-I <`y-H
break; 4T(d9y
} IS&qFi}W|W
} 63Zu5b"O/
catch(IOException e){e.printStackTrace ();} @!fUp b
catch(Exception e){e.printStackTrace ();} &]o-ZZX
XQ}J4J~Vm
8C@u+tx
Utility.log(nFileLength); /S]RP>cQ
W+!UVUpW
AE}cHBwZE
return nFileLength; o'$"MC+
} ]6^<VC`5D
g=$U&Hgs
8xO
//保存下载信息（文件指针位置） !2KQi=Ng
private void write_nPos() ~dr,;NhOLJ
{ o@zxzZWg
try{ :TU|:2+
output = new DataOutputStream(new FileOutputStream(tmpFile)); ZQE1]ht
output.writeInt(nStartPos.length); z qq
for(int i=0;i<nStartPos.length;i++) VQHB}Y@^
{ \uOM,98xS
// output.writeLong(nPos); '_G\_h}5
output.writeLong(fileSplitterFetch.nStartPos); Ahwi
output.writeLong(fileSplitterFetch.nEndPos); sWo`dZ\6WB
} \s&Mz;:
output.close(); -p_5T*R
} d=xjLbsZ
catch(IOException e){e.printStackTrace ();} _J!^iJ
catch(Exception e){e.printStackTrace ();} h5'hP>b#
} &|Duc} t
?"9h-g3`x}
Lmte ~oBi
//读取保存的下载信息（文件指针位置） mp8GHV
private void read_nPos() 88osWo6rG
{ 60!%^O =
try{ _eiqs
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6/8K2_UeoW
int nCount = input.readInt(); (NvjX})eh
nStartPos = new long[nCount]; PK2;Ywk`
nEndPos = new long[nCount]; v;<gCzqQh
for(int i=0;i<nStartPos.length;i++) 5U~KYy^v
{ JPqd}:u3
nStartPos = input.readLong(); %, psUOY
nEndPos = input.readLong(); +-@n}xb@
} |&=-Nm
input.close(); <l5i%?
} =tP9n;D
catch(IOException e){e.printStackTrace ();} FYYc+6n
catch(Exception e){e.printStackTrace ();} T%eBgseS
} }:IIk-JoC
fwz:k]vk
}N[X<9^Z
private void processErrorCode(int nErrorCode) zkRAul32|
{ U9:)qvMXe
System.err.println("Error Code : " + nErrorCode); t`H1]`c?
} _U^[h!
~9+01UU^
d^}p#7mB\
//停止文件下载 H]/~ #a
public void siteStop() " !EnQB=
{ M_ukG~/
bStop = true; K'ZNIRr/C
for(int i=0;i<nStartPos.length;i++) !vgY3S0?rq
fileSplitterFetch.splitterStop(); LIcc0w3
[LnPV2@e
fmz"Zg9=
} 3@V?L:J
} <==uK>pET
//负责部分文件的抓取 :'DyZy2Fd
**FileSplitterFetch.java l/G+Xj4M
*/ dxs5woP
package NetFox; lr>NG,N
[ey# ,&T
Q ]CMm2L^f
import java.io.*; @njNP^'Kx
import java.net.*; "u^Erj# /
'v]0;~\mp>
$NVVurXa
public class FileSplitterFetch extends Thread { AZ3T#f![L@
.|O T#"LP
MIZdk'.U
String sURL; //File URL |_TiF;^
long nStartPos; //File Snippet Start Position > ubq{'
long nEndPos; //File Snippet End Position 7\ _MA!:<
int nThreadID; //Thread's ID q%4X1 W
boolean bDownOver = false; //Downing is over S oeoUI]m
boolean bStop = false; //Stop identical i&:SWH=
FileAccessI fileAccessI = null; //File Access interface x []ad"R
@ 8H$
Fe0M2%e;|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *-9i<@|(U^
{ OvX&5Q5
this.sURL = sURL; {nKw<F2
this.nStartPos = nStart; ' 4FH9J
this.nEndPos = nEnd; z}MxMx c4h
nThreadID = id; M1/d7d
fileAccessI = new FileAccessI(sName,nStartPos);//定位 KHAc!4lA
} \AwkK3
"A}sD7xy9
6'^E ],:b
public void run() ;TJpD0
{ L(;$(k-/(
while(nStartPos < nEndPos && !bStop) O{l4 f:51
{ zTa5N
So&gDR;b
/"Vd( K2Z
try{ r%=-maPL[
URL url = new URL(sURL); B"_O!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b-<0\@`Z#
httpConnection.setRequestProperty("User-Agent","NetFox"); v?VDASR2`
String sProperty = "bytes="+nStartPos+"-"; >Q/;0>V
httpConnection.setRequestProperty("RANGE",sProperty); V$ H(a`!
Utility.log(sProperty); h <4`|Bg+
/i,n75/y?
Lu}jk W*
InputStream input = httpConnection.getInputStream(); "QnYT3[l"
//logResponseHead(httpConnection); c~vhkRA
\n[kzi7
VCWW(Y1Fd
byte[] b = new byte[1024]; I<#X#_YP
int nRead; $+Ze"E
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Lk !)G'42
{ ov_l)vt
nStartPos += fileAccessI.write(b,0,nRead); +aOdaNcI
//if(nThreadID == 1) I}_}VSG(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BY~Tc5
} vIRT$W' O}
r:bJU1P1$s
qofAA!3z
Utility.log("Thread " + nThreadID + " is over!"); EHC7b^|3}
bDownOver = true; 6B?jc/V.R
//nPos = fileAccessI.write (b,0,nRead); N9!L8BBaK
} #yH+ENp0
catch(Exception e){e.printStackTrace ();} =de'Yy:\-
} ]6e(-v!U
} Jc#D4e1#
i.t%a{gL
G!6b )4L-
//打印回应的头信息 &[[r|
public void logResponseHead(HttpURLConnection con) Nm"P8/-09
{ NBPP?\1
for(int i=1;;i++) >/A]C$?3
{ hoq2zDjD
String header=con.getHeaderFieldKey(i); c& ;@i$X(
if(header!=null) ~q3O,bb{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); OyO]; Yk
Utility.log(header+" : "+con.getHeaderField(header)); Rn?JMM]
else FaeKDbLJr
break; 9vV==A#
} 3&y-xZu]
} / dJz?0
hVF^"$
:IZAdlz[@
public void splitterStop() yh E%X
{ +VkL?J
bStop = true; 8._uwA<[
} IAQ<|3Q
(F&LN!Hn>p
EIRDH'[L
} zP44 Xhz
G%I .u
dx@dnWRT,
/* G!Brt&_'
**FileAccess.java 3Q$4`p;
*//文件访问(定位，写) ;5ki$)v"
package NetFox; =Ydrct
import java.io.*; >=0]7k;
T_D3WHp
%>&ex0j]
public class FileAccessI implements Serializable{ k;^$Pd?t
z6R|1L 1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p-iFe\+
RandomAccessFile oSavedFile; _{jC?rzb
long nPos; Z^>4qf,k
D3C7f'
fQ5v?(
public FileAccessI() throws IOException C][$0
{ fB+h( 2N~
this("",0); -~]H5er`
} Mc,|C)
O.+J%],
y$%oR6K7-
public FileAccessI(String sName,long nPos) throws IOException 7Y8~")f
{ <YW)8J
oSavedFile = new RandomAccessFile(sName,"rw"); Z{B e
this.nPos = nPos; W4o8]&A
oSavedFile.seek(nPos); r.eK;
} dcY(1p)
RHFRN&RU$
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public synchronized int write(byte[] b,int nStart,int nLen) %'1iT!g8
{ cTq@"v di
int n = -1; 4G,FJjE`p
try{ 2 q4p-
oSavedFile.write(b,nStart,nLen); 9K@I
n = nLen; &\9%;k
} f- XUto
catch(IOException e) &<;T$Y
{ vqN/crJ@
e.printStackTrace (); r,JQR)l0@V
} /Z6lnm7wJ
[_JdV(]$
vi}16V84l
return n; Ca'BE#q
} Ro]Z9C>1o
`-{l$Hn9|~
*,z/q6
} s>/Xb2\
{g.YGO
YIRe__7-NU
/* + Tp% *
**SiteInfoBean.java lMFo)4&P
*/ K? o p3}f?
package NetFox; |aP`hVm
S=,czs3N
l6bY!I>
public class SiteInfoBean { EsKgS\`RZ
hV(^Y)f
Z;G*wM"
private String sSiteURL; //Site's URL F- -g?Q^
private String sFilePath; //Saved File's Path D>y5&`
private String sFileName; //Saved File's Name &)OI!^ (
private int nSplitter; //Count of Splited Downloading File Zye04&x9k
"Ol:ni1
zwV!6xG
public SiteInfoBean() \ UrD%;sq
{//nSplitter的缺省值为5 08xo_Oysq
//default value of nSplitter is 5 X:UlL"G
this("","","",5); KdkL_GSLT
} |yk/iO(
)pl5nu#<
y7>3hfn~w
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) S'!&,Dxq^
{ |~5cNm
sSiteURL= sURL; TBt5Nqks-
sFilePath = sPath; GM2}]9
sFileName = sName; { YQS fk
this.nSplitter = nSpiltter; r2SZC`Z}-M
{Phq39g
RTh=x.
} O8 .iP+
v's1&%sM
d'96$e o~
public String getSSiteURL() /''=V.-N
{ f!kZyD7
return sSiteURL; uZL]mwkj]
} 4m<]qw
skl3/!
6m$X7;x}
public void setSSiteURL(String value) =;-C;gn:w
{ =Smd/'`_
sSiteURL = value; {j$2=0Cec
} i975)_X(
4"@;.C""
?7NSp2aq2A
public String getSFilePath() UK,bfLPt~
{ .L^*9Y0)
return sFilePath; WkiT,(i
} 6agq^wI
6#Z]yk+p
/}6I3n
public void setSFilePath(String value) B/l^=u+-
{ +\Vw:~e
sFilePath = value; ~+1mH
} KfjWZ4{v
_+48(QF<
?+EAp"{j
public String getSFileName() UWO3sZpU
{ /V*SI!C<f
return sFileName; F% n}vA`
} (W h)Ov"
{Lal5E4-
Q&W>h/
public void setSFileName(String value) 1\( N,'h
{ [TA.|7&
sFileName = value; /!0&b?
} `T*Y1@FV
x(HHy,
-ZE YzZqY
public int getNSplitter() </;e$fh`
{ .hH_1Mo8
return nSplitter; l1T`[2
} Z$J-4KN
4}DFCF%B
)K?7(H/j
public void setNSplitter(int nCount) 02Vfg42
{ a2.6S./
nSplitter = nCount; xwo*kFg
} [KR%8[e
} ^S`hKv&87
2n3&uvf'TL
f5F-h0HF`[
/* bz>\n"'
**Utility.java B0yJ9U= Fj
*/ C5^WJx[
package NetFox; q>(?Z#sB
((`\i=-o5
)&T 5/+
public class Utility { FDgo6x
K9ia|2f
m Z +dr[
public Utility() v_Vw!u
{ e'uC:O.u
)w4U]inJ$"
HlX~a:.7
} ?ja%*0 R
o*A, 6y
//线程睡眠 U+'zz#0qN
public static void sleep(int nSecond) 0&)6mO
{ Njg87tKB
try{ K/B$1+O
Thread.sleep(nSecond); [_%u5sc-y
} X~&8^?
catch(Exception e) $yi:0t8t
{ G0!6rDu2,
e.printStackTrace (); H_@6!R2
} DNZ,rL:h
} b4wT3
}&+,y<>
//日志 _*UI}JtlS
public static void log(String sMsg) :q3w;B~
{ 3:Nc`tM_
System.err.println(sMsg); !2Ompcr1
} 1\,k^Je7
Gjeb)Y6N
*~GI-h
public static void log(int sMsg) :ILpf+`yY
{ (hOD
System.err.println(sMsg); Il4]1d|
} MOh&1]2j5
} ~x(|'`
iLv -*%%
:%9R&p:'ar
/* P7W|e~]Yq
**TestMethod.java ?,7!kTRH
*/ d#+Nef5
package NetFox; o:v_I{
!S&/Zp
?@PSD\
public class TestMethod { e46`"}r
|pZ7k#%
]8wm1_qV
public TestMethod() rAtCG1Vr
{ ///xx/weblogic60b2_win.exe j]&Qai~}Y
try{ GU`q^q@Ea
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?i_/f}.K
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }Ifa5Lq)
SiteFileFetch fileFetch = new SiteFileFetch(bean); p>pN?53S
fileFetch.start(); '*XIp:
} I}u\ov_Su
catch(Exception e){e.printStackTrace ();} 0`.&U^dG
|WS@q'
i 1w]j
} evZP*N~G
p#w8$Qjp
u9Adu`
public static void main(String[] args) B&B4 P
{ h-Y>>l>PW0
new TestMethod(); Tv'1IE
} pHb,*C</
} DjaXJ?'
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