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)); lcUL7
} #a .aD+d'
for(int i=0;i<nEndPos.length-1;i++) ;c;;cJc!
{ ]]7s9PCN
nEndPos = nStartPos[i+1]; CX1'B0=\r
} 'E7|L@X"r
nEndPos[nEndPos.length-1] = nFileLength; |20p#]0E+
} LXK+WB/s
} Sk1yend4
V'6%G:?0a
UhEnW8^bz1
//启动子线程 wEkW=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3b[_0
for(int i=0;i<nStartPos.length;i++) (JF\%Yj/
{ QTLOP~^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =j}00,WH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ur@'X-
nStartPos,nEndPos,i); FD`V39##
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IzL yn
fileSplitterFetch.start(); TnKe"TA|9
} Zd5frc$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |H |ewVUY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); sXfx[)T<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", k*n5+[U^tP
nEndPos = " + nFileLength); =XWi+')
// fileSplitterFetch[nPos.length-1].start(); =nY*,Xu<
@0)bY*njj
2smLv1w@
//等待子线程结束 : 0%V:B
//int count = 0; ( E0be.
//是否结束while循环 k@wxN!w;
boolean breakWhile = false; y\@XW*_?
0<P -`|X
R"82=">v
while(!bStop) RQh4RUm
{ icnp^2P
write_nPos(); A46y?"]/30
Utility.sleep(500); k|g~xmI;
breakWhile = true; IPY@9+]
M<)HJ lr
gGZ$}vX
for(int i=0;i<nStartPos.length;i++) GbMSO
{ zx\?cF
if(!fileSplitterFetch.bDownOver) YxsWY7J
{ g@S"!9[;U
breakWhile = false; l9SbuT$U
break; hx:x5L>
} ^c-1wV`/
} v4 c_UFEh<
if(breakWhile) TYB^CVSZ
break; P [gqv3V
M~wJe@bc
o,X ?
//count++; FfP Ce5)
//if(count>4) 8-po|
// siteStop(); J.*dA j
} jT'1k[vJj
hDfsqSK0 /
cQN}z Ke
System.err.println("文件下载结束！"); ;up89a-,9
} @y}1%{,%
catch(Exception e){e.printStackTrace ();} R[Pyrs!H
} q,+d\-+
_STN^
P/0n) Q
//获得文件长度 j4Lf6aUOX
public long getFileSize() y=q\1~]Z
{ ~xzRx$vU
int nFileLength = -1; 6{1c S
try{ <G#JPt6
URL url = new URL(siteInfoBean.getSSiteURL()); eyUo67'7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); IF@)L>-%
httpConnection.setRequestProperty("User-Agent","NetFox"); Rb\\6BU0
(uRAK
$%sOL( r
int responseCode=httpConnection.getResponseCode(); 4GaF:/
if(responseCode>=400) p+A#t~K
{ S^~GI$
processErrorCode(responseCode); >D*L0snjV
return -2; //-2 represent access is error +]Ydf^rF
} NbfV6$jo
-4"E]f
Oi=kL{DG:s
String sHeader; VBsS1!g
{6A3?q
&s\w: 9In
for(int i=1;;i++) Lymy/9
{ Ga$+x++'*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Xgc@cwd
//Utility.log(in.readLine()); XG*Luc-v
sHeader=httpConnection.getHeaderFieldKey(i); 6x6PP}IX
if(sHeader!=null) .3!=]=
{ >H?8?a D
if(sHeader.equals("Content-Length")) rsA K0R+
{ HPm12&8,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C:zK{+
break; FhS:.
} ?MyXii<a
} e=TB/W_
else vA:1z$m
break; X8p-VCkV
} De\&r~bTW9
} Ll%[}C?~]?
catch(IOException e){e.printStackTrace ();} $^}?98m
catch(Exception e){e.printStackTrace ();} }"%tlU!}
Bo_Ivhe[m
9>\s81^
Utility.log(nFileLength); b=`h""u
xR\$2(
27G6C`}
return nFileLength; 0Ocy$
} t%V!SvT8+
8`kK)iCq
Mb uD8B
//保存下载信息（文件指针位置） XeKIue@_
private void write_nPos() HTvA]-AuM
{ 8(7DW |\
try{ +P81&CaY
output = new DataOutputStream(new FileOutputStream(tmpFile)); Hh4$Qr;R
output.writeInt(nStartPos.length); BUuNI_?M#5
for(int i=0;i<nStartPos.length;i++) iLNKC'
{ JZ]4?_l
// output.writeLong(nPos); tJ i#bg%
output.writeLong(fileSplitterFetch.nStartPos); b_:]Y<{> f
output.writeLong(fileSplitterFetch.nEndPos); m "h{HgJd
} seB ^o}
output.close(); -y)ij``VY
} }RDGk+x7|
catch(IOException e){e.printStackTrace ();} oxha8CF]D
catch(Exception e){e.printStackTrace ();} >7p?^*&7;
} SBgBZm}%
3g`uLA X>u
:q<8:,rP
//读取保存的下载信息（文件指针位置） 00[Uk'Q*5
private void read_nPos() n0:'h}^
{ a2SMNC]
try{ xJ:15eDC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g VplBF7{
int nCount = input.readInt(); m?V4r#t
nStartPos = new long[nCount]; bF0y`
nEndPos = new long[nCount]; 4%0eX]
for(int i=0;i<nStartPos.length;i++) #ih(I7prH
{ T'"aStt6
nStartPos = input.readLong(); Np$pz
nEndPos = input.readLong(); odD^xg"L
} kG^DHEne
input.close(); /Q8E12
} ?YOH9%_cs
catch(IOException e){e.printStackTrace ();} Lo5itW
catch(Exception e){e.printStackTrace ();} !-_0I:m
} rzsb(
[kM)K'-
vT#zc)j
private void processErrorCode(int nErrorCode) Ep>3%{V
{ s{4|eYR
System.err.println("Error Code : " + nErrorCode); # y%Q{
} %O#)=M~
R'`q0MoN1
UR>zL3
//停止文件下载 $e)d!m.
public void siteStop() J=JYf_=4bc
{ ~Pq1@N>n
bStop = true; FctqE/>}I
for(int i=0;i<nStartPos.length;i++) oi^2Pvauh
fileSplitterFetch.splitterStop(); 33z)F
^1sX22k
lTBPq?4{
} *NHBwXg+
} \09eH[
//负责部分文件的抓取 _~ZNX+4
**FileSplitterFetch.java /7/d u[P6
*/ OXd617
package NetFox; B2w\
-!f)P=S
"l&=a1l
import java.io.*; 8QDs4Bv|
import java.net.*; TPH`{
ViIt'WX
$hZb<Xz
public class FileSplitterFetch extends Thread { sEP-jEuwG
fl#gWAM
(Z;;v|F.i=
String sURL; //File URL <5X?6*Qvr
long nStartPos; //File Snippet Start Position r~&"D#)sy
long nEndPos; //File Snippet End Position #; CC"
int nThreadID; //Thread's ID >>oR@
boolean bDownOver = false; //Downing is over #9M6 q
boolean bStop = false; //Stop identical ^x-vOGlR
FileAccessI fileAccessI = null; //File Access interface uu@Y]0-
B8;jRY
PY- 1 oP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /n;Ll](ri
{ :34]}`-
this.sURL = sURL; `?r]OVe{y
this.nStartPos = nStart; S{'/=Px+
this.nEndPos = nEnd; ErIAS6HS'
nThreadID = id; U]jHe
fileAccessI = new FileAccessI(sName,nStartPos);//定位 KE!aa&g
} `@1y|j:m
lO3W:,3_a
dfl| 6R
public void run() S<HR6Xw
{ pESlBQ7{I
while(nStartPos < nEndPos && !bStop) =oQw?,eY
{ +y'V
^PA >t$
x(pq!+~K
try{ c@;$6WSG^
URL url = new URL(sURL); ilJeI@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); = }0M^F
httpConnection.setRequestProperty("User-Agent","NetFox"); {5w'.Z]0v
String sProperty = "bytes="+nStartPos+"-"; (WZKqt)S"o
httpConnection.setRequestProperty("RANGE",sProperty); 0goKiPx
Utility.log(sProperty); "h?;)Ye
K;moV| j
:ZG^`H/X1d
InputStream input = httpConnection.getInputStream(); &9X`tCnL
//logResponseHead(httpConnection); -;9pZ'r
|`d,r.+P7
['~j1!/;6
byte[] b = new byte[1024]; '?7th>pC
int nRead; ii&{gC
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) b Lag&c)
{ ~_<I}!j/B
nStartPos += fileAccessI.write(b,0,nRead); $.{CA-~%[
//if(nThreadID == 1) KzD5>Xf]4$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o (fZZ`6Y
} g-lF{Z
5y-8_)y8o
AKs=2N>7
Utility.log("Thread " + nThreadID + " is over!"); C$Pe<C#
bDownOver = true; 2ED^uc: 0S
//nPos = fileAccessI.write (b,0,nRead); gSLwpIK%
} 5dOA^P@`,M
catch(Exception e){e.printStackTrace ();} %.^8&4$+
} =qPk'n9i8
} Q-;ltJ
N5 ITb0Tv
}%LwaRT
//打印回应的头信息 `~|8eKFq!
public void logResponseHead(HttpURLConnection con) pgT XyAP{
{ U7O]g'BP
for(int i=1;;i++) 6&V4W"k
{ \;AW/&Ea
String header=con.getHeaderFieldKey(i); ~um+r],@@
if(header!=null) ;m6Mm`[i<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wUkLe-n,dE
Utility.log(header+" : "+con.getHeaderField(header)); 3?|gBiX
else gEC*JbA.3
break; F%QZe*m[
} p_h)|*W{
} *4}lV8
$__e7
qZRx,^gd
public void splitterStop() 04-phEA2Q
{ Cr0 \7
bStop = true; Y#'mALC2
} qT]Bl+h2
jRIjFn|~{Y
. 2_t/2
} /;LteBoY
k1;,eB
JHpoW}7QB
/* pL`snVz
**FileAccess.java ONQp-$
*//文件访问(定位，写) KI(9TI*
package NetFox; - bL 7M5
import java.io.*; +o&E)S}wP
VU,\OOp
9HMW!DSK`
public class FileAccessI implements Serializable{ AMqu}G
: sIZ+3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 G#V5E)Dx
RandomAccessFile oSavedFile; w`XwW#!}@$
long nPos; `K[:<p}
tm\ <w H
wqDRFZ1*P
public FileAccessI() throws IOException g*8LdH6mq
{ 6_/oVvd
this("",0); !ZP1?l30
} |u8hxa
X;_0"g
c)Ft#vzg&e
public FileAccessI(String sName,long nPos) throws IOException #u+BjuZo
{ 6w{^S~rqo
oSavedFile = new RandomAccessFile(sName,"rw"); 2,|*KN*e`W
this.nPos = nPos; =y>P>&sI
oSavedFile.seek(nPos); 0^44${bA
} 3}O.B r|
g3{)AX[Uy
e #l/jFJU
public synchronized int write(byte[] b,int nStart,int nLen) rN? L8
{ -F,o@5W>Y
int n = -1; U,/NygB~
try{ R`=IYnoOA
oSavedFile.write(b,nStart,nLen); #|*;~:fz
n = nLen; }8WpX2U
} #r 1 $=GY
catch(IOException e) z79L2lJn
{ |7WzTz
e.printStackTrace (); &|<~J(L;
} .UbmU^y|
;@K,>$ur-
G[u_Uu=>
return n; Q(m} Sr4
} G8|[.n
AG)N^yd
[:$j<}UmB
} /b@0HL?
>K#Z]k
Jl3l\I'
/* !7J;h{3Uw
**SiteInfoBean.java Z91gAy^z<
*/ +Cx~4zEq
package NetFox; "r cPJX
9b]*R.x:$&
~QBf78@Gf
public class SiteInfoBean { $';'MoS
S,AZrgh,"X
l@1f L%f
private String sSiteURL; //Site's URL sLbz@54
private String sFilePath; //Saved File's Path toTAWT D
private String sFileName; //Saved File's Name /dOQ4VA\
private int nSplitter; //Count of Splited Downloading File =i%2/kdi0b
PyYKeo=
0x^$q? \A
public SiteInfoBean() T<zonx1
{//nSplitter的缺省值为5 cdU2ph_
//default value of nSplitter is 5 R$,`}@VqZ3
this("","","",5); nq/xD;q
} ?0[%+AD hM
&[cL%pP
w])~m1yW
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ec1g7w-n
{ 4EB$e?
sSiteURL= sURL; eV9:AN}K=
sFilePath = sPath; K1:F{*
sFileName = sName; 2SG|]=
this.nSplitter = nSpiltter; ^0{S!fs
m_rRe\
.e.vh:Sz
} oK5(,8 (4
8GlH)J+kq
Rz=]KeZu
public String getSSiteURL() |w~zh6~
{ rLL;NTN+/
return sSiteURL; ]v_xEH}T
} MW*}+ PCY
iXl1S[.l
DA@ { d-A
public void setSSiteURL(String value) [&3"kb
{ NlcWnSv
sSiteURL = value; ,7%(Jj$ ^
} ;o^m"I\y
G#@<bg3
;k/0N~
public String getSFilePath() ^;@Bz~Z
{ '3hvR4P
return sFilePath; ^* DKF
} :+Dn]:\
KAsS= `
KMbBow3o*~
public void setSFilePath(String value) GUN<ZOYb=
{ Ds}6{']K
sFilePath = value; Wnf`Rf)1z
} |=%$7b\C
a}>GQu*y
J.?p?-"
public String getSFileName() ae!_u \$
{ }f-rWe{gs>
return sFileName; IL%&*B
} W2^eE9
aO<d`DTyJ
nAts.pVy"
public void setSFileName(String value) V|a59[y?
{ 9h0|^ttF
sFileName = value; > %Y#(_~a
} nQ~q-=,L
uwQ4RYz
,MvvW{EY
public int getNSplitter() MPL2#YU/a
{ 1}ToR=
return nSplitter; [e^i".
} ;N1FP*
k2+Z7#2n
}<Me%`x"
public void setNSplitter(int nCount) ?1412Tq5
{ +M.|D,wg2
nSplitter = nCount; rW6w1
} *v5y]E%aW
} a9qZI
g)p[A 4
%##9.Xm6l
/* 1^W Aps
**Utility.java Bkz
*/ JGdBpj:
package NetFox; 9a4RW}S<
;zJ_apZ:{
%vThbP#mR|
public class Utility { _9gn;F
C3<3
[X=eCHB?
public Utility() X0P$r6 ;
{ ePY K^D
eb8_guZ
Q@j:b]Y9
} q{5Vq_s\
oDP|>yXC)
//线程睡眠 }`g*pp*
public static void sleep(int nSecond) Anm5Cvt;i
{ Ux<h` s
try{ Fwqv1+
Thread.sleep(nSecond); _j2`#|oG
} kN) pi "
catch(Exception e) *lTu-
{ JC+VG;kcs
e.printStackTrace (); w'eenIX^^
} QMsnfG
} EPg?jKZava
e,4G:V'NX
//日志 F3f>pK5
public static void log(String sMsg) Bh.'%[',
{ 'qD9kJ`
System.err.println(sMsg); tw(2V$J
} %B?5l^W@
z>&D~0
d+w<y~\ q
public static void log(int sMsg) jGWLYI=V2
{ 3z ry %qV=
System.err.println(sMsg); BA5= D>T-
} x~z 2l#ow
} -|T^
Af%?WZlOq
FPMk&
/* ;K_B,@:'
**TestMethod.java ditzl(L
*/ x?F{=\z/o
package NetFox; p?h;Sv/
INT2i8oU
zJy{Ry[Sb
public class TestMethod { %)e+w+
*~"`&rM(
&ar}6eO
public TestMethod() g\Zk*5(
{ ///xx/weblogic60b2_win.exe aD^MoB3
try{ @88 efF
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D0P% .r"v
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9%wppNT/
SiteFileFetch fileFetch = new SiteFileFetch(bean); q8lK6p\:W
fileFetch.start(); r6)1Y`K=9
} n" ~*9'
catch(Exception e){e.printStackTrace ();} pWp2{G^XB
r/v&tU
+OmSR*fA0
} ig,|3(
vOS0E^
5zGj,y>u
public static void main(String[] args) WWLVy(
{ _7<U[63
new TestMethod(); :6 fQE#(s&
} QUDVsN#
} Ss:,#|
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