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)); yl-fbYH
} iJdP>x
for(int i=0;i<nEndPos.length-1;i++) Ly9Q}dL
{ 3Y z]8`C
nEndPos = nStartPos[i+1]; .^i<xY
} z%V*K
nEndPos[nEndPos.length-1] = nFileLength; DVI7]+=nV
} ITyzs4"VV
} !?nu?
EeCFII
iTh xVD
//启动子线程 H]s4% 9T
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #?9Q{0e
for(int i=0;i<nStartPos.length;i++) uBmxh%]C~
{ bV@7mmz:X+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Wo{K}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I:#Ok+
nStartPos,nEndPos,i); :pwa{P
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3bH~';<
fileSplitterFetch.start(); tPA:_
} p8=|5.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Qyz>ZPu}sz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {XtoiI
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0[/vQ+O]2
nEndPos = " + nFileLength); -kl;!:'.3
// fileSplitterFetch[nPos.length-1].start(); A 4j<\xL
$uCiXDKCq
XaW4C-D&
//等待子线程结束 tBseqS3<
//int count = 0; a/~29gW8E\
//是否结束while循环 uPkb, :6~Z
boolean breakWhile = false; `<^*jB@P
u_.HPA
6xarYh(
while(!bStop) ASW4,%cl
{ ivfXat-
write_nPos(); cC%j!8!
Utility.sleep(500); jYWw.g<
breakWhile = true; e*:}$u8a
{"m0)G,G
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for(int i=0;i<nStartPos.length;i++) =}v ;1m
{ WSLy}@`Vx
if(!fileSplitterFetch.bDownOver) :uo[&&c
{ UfR~%p>K
breakWhile = false; H`-=?t
break; MiJ6n[iv
} qD-fw-,:
} ?E<c[*F05
if(breakWhile) V&i2L.{G)
break; .+yW%~0
R)+t]}
R}r~p?(M
//count++; "jR]MZ
//if(count>4) HzvlF0f
// siteStop(); ,=|4:F9
} Vl<9=f7[
ne4c%?>t
H4:ZTl_$
System.err.println("文件下载结束！"); QR"bYQ
} =&Xdm(
catch(Exception e){e.printStackTrace ();} 0|XKd24BN
} =Vb~s+YW
, T\-;7
~c* UAowS
//获得文件长度 bLbR IY"l
public long getFileSize() s<vs:jna
{ t`5j4bdG
int nFileLength = -1; zAs&%OjG
try{ ;W{b $k@g
URL url = new URL(siteInfoBean.getSSiteURL()); MzzKJ;wbC6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9#k0_vDoW
httpConnection.setRequestProperty("User-Agent","NetFox"); CISO<z0
#Qh>z%Mn^3
dl0FQNz8@B
int responseCode=httpConnection.getResponseCode(); -$JO8'TP
if(responseCode>=400) b,@aqu
{ %d;<2b0
processErrorCode(responseCode); tnb$sulc+
return -2; //-2 represent access is error .9h)bf+
} 5G(E&>~
k_aW
DM),|Nq"
String sHeader; {.CMD9F[
uWjU OJEe
C\Vg{&'
for(int i=1;;i++) .Evy_o\^
{ Izo!rC
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %NajFjBI
//Utility.log(in.readLine()); bik*ZC?E
sHeader=httpConnection.getHeaderFieldKey(i); K2rzhHfb
if(sHeader!=null) T8XY fcc*h
{ 3o6RbW0[
if(sHeader.equals("Content-Length")) $`ztiVu3
{ ?6P.b6m}0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); jL>:>r
break; 1] #9
} K |*5Kwi
} G[Tl%w
else gU1#`r>[)
break; CO^Jz
} cCiI{
} ~R]35Cp-#
catch(IOException e){e.printStackTrace ();} "A3dvr
catch(Exception e){e.printStackTrace ();} :%X Ls,
S8vV!xO
E m{aM
Utility.log(nFileLength); XOy2lJ/
}Ln@R~[
,gx)w^WTm
return nFileLength; 3[IJhR[
} 9}P"^N
^6;V}2>v}
1;lmu]I>)
//保存下载信息（文件指针位置） qpp/8M
private void write_nPos() M\D]ml~
{ ;inzyFbL=
try{ %Mn.e a
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1n=_y o
output.writeInt(nStartPos.length); L":bI&V?:
for(int i=0;i<nStartPos.length;i++) H!)=y
{ x_MJJ(q8g
// output.writeLong(nPos); CN&
output.writeLong(fileSplitterFetch.nStartPos); *>q/WLR
output.writeLong(fileSplitterFetch.nEndPos); Bh]!WMAw.
} 'Ot,H_pE
output.close(); Yu3zM79'k
} /rc%O*R
catch(IOException e){e.printStackTrace ();} $m| V :/
catch(Exception e){e.printStackTrace ();} v;EQ, NL
} -db75=
\3XqHf3|o
>mq,}!n
//读取保存的下载信息（文件指针位置） mD58T2Z
private void read_nPos() jd-glE,Y/
{ F<&!b2)ML
try{ LnsD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;xYNX
int nCount = input.readInt(); CE%_A[a
nStartPos = new long[nCount]; ?]O7Ao
nEndPos = new long[nCount]; kv{}C)kt3
for(int i=0;i<nStartPos.length;i++) ?> Dtw#}
{ g);^NAA
nStartPos = input.readLong(); hJ;$A*Y
nEndPos = input.readLong(); EbY,N:LK
} 'gMfN
input.close(); ,&^3Z
} ,)FdRRj
catch(IOException e){e.printStackTrace ();} aA'TD:&p1
catch(Exception e){e.printStackTrace ();} B4Y(?JTx
} #*%q'gyHT
vH[47CvG5
Nw_@A8-r
private void processErrorCode(int nErrorCode) #qBr/+b
{ nY%5cJ`"
System.err.println("Error Code : " + nErrorCode); +IFw_3$
} XGrue6ya
t= #&fSR
S$q=;"
//停止文件下载 AyKMhac
public void siteStop() NAC_pM&B
{ fwR_OB:$
bStop = true; 7- d.ZG
for(int i=0;i<nStartPos.length;i++) <O<LYN+(
fileSplitterFetch.splitterStop(); (!L5-8O
4u;9J*r4
*/qtzt
} YIRZ+H<Q
} ~uWOdm-"[
//负责部分文件的抓取 13k !'P
**FileSplitterFetch.java (2ot5x}`j
*/ Sjj>#}U
package NetFox; =8Jfgq9E
=T?}Nt
/phX'xp
import java.io.*; -fI`3#
import java.net.*; 7cDU2l
{Azn&|%.t
LpbsYl
public class FileSplitterFetch extends Thread { v X~RP *
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o G*5f
String sURL; //File URL G3P&{.v
long nStartPos; //File Snippet Start Position /6uT6G+(z}
long nEndPos; //File Snippet End Position LkruL_E>
int nThreadID; //Thread's ID CqMhk
boolean bDownOver = false; //Downing is over Cwa^"r3P1
boolean bStop = false; //Stop identical (& "su3z
FileAccessI fileAccessI = null; //File Access interface ipnV$!z
yOU(2"8p
2jJmE&)7,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException BXms;[
{ hg.#DxRi{
this.sURL = sURL; ^nJyo:DO;
this.nStartPos = nStart; ?Ea;J0V
this.nEndPos = nEnd; 5zJj]A
nThreadID = id; ^FmU_Q0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "Mw[P [w*
} 7"F*u :
Ks^6.)
v4,h&JLt
public void run() (_kp{0r#
{ g,tjm(
while(nStartPos < nEndPos && !bStop) Pt:e!qX)
{ RcG0 8p.)
-H^oXeN
E907fX[R~
try{ Ix@&$!'k
URL url = new URL(sURL); >zsid:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /-_=nf}w
httpConnection.setRequestProperty("User-Agent","NetFox"); ( 9!k#
String sProperty = "bytes="+nStartPos+"-"; h+p*=|j`
httpConnection.setRequestProperty("RANGE",sProperty); {^mNJ
Utility.log(sProperty); {e[%;W%c&
=!O*/6rz
<U5wB]]
InputStream input = httpConnection.getInputStream(); uzmk6G v
//logResponseHead(httpConnection); 4'j sDcs
8KB>6[H!wE
jUv!9Y}F
byte[] b = new byte[1024]; 4(e59ZgY
int nRead; =L%DX#8
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) kIw`P[
{ [${ QzO
nStartPos += fileAccessI.write(b,0,nRead); MObt,[^W
//if(nThreadID == 1) 'j^xbikr
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]V %.I_
} WARb"8Kg
}I|u'#n_
;k"Bse!/
Utility.log("Thread " + nThreadID + " is over!"); iLP7!j
bDownOver = true; 9CA^B2u
//nPos = fileAccessI.write (b,0,nRead); UDhG :
} =9oPowq
catch(Exception e){e.printStackTrace ();} 2"|2a@
} p.ANVA@:
} B\J^=W+`
V@>r*7\F
GRb*EeT
//打印回应的头信息 ] h-,o R?e
public void logResponseHead(HttpURLConnection con) q)H1pwxD
{ ?88[|;b3
for(int i=1;;i++) .)}@J5P)
{ /V3=KY`_J
String header=con.getHeaderFieldKey(i); Q9I j\HbA"
if(header!=null) WLF0US'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8^Hn"v
Utility.log(header+" : "+con.getHeaderField(header)); }I3gU
else G+B~Ix-
break; Z3>N<u8)
} a#mNE*Dg
} X37L\e[c
,yd MU\so(
FX9F"42@
public void splitterStop() SH*C"
{ aQI^^$9g
bStop = true; `D9]*c !mO
} :4~g;2oag
<;E
`_b`kzJ
} ;Yi4Xva@
)jq?lw'&
0sI1GhVR
/* y=In?QN{6*
**FileAccess.java M?=;JJ:
*//文件访问(定位，写) da1]mb=4 5
package NetFox; *),8PoT
import java.io.*; OB[o2G<0
'n<iU st
y5Tlpi`g
public class FileAccessI implements Serializable{ GUF"<k
Bo<>e~6P
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 D:Q 21Ch
RandomAccessFile oSavedFile; IbcZ@'RSw
long nPos; >^Se'SE]
-n'F v@U
)c l5B{1P
public FileAccessI() throws IOException aM7uBx\8 5
{ >A0k 8T
this("",0); RI68%ZoL
} sXd8rj:o
gN)c
;raN
public FileAccessI(String sName,long nPos) throws IOException e/->_T(I
{ -P&6L\V
oSavedFile = new RandomAccessFile(sName,"rw"); h3T9"w[
this.nPos = nPos; 9f\/\L
oSavedFile.seek(nPos); \rVQQ|l
} 7' S@3
=)hVn
3!5Ur&
public synchronized int write(byte[] b,int nStart,int nLen) O?<&+(uMTT
{ _EF&A-kX|u
int n = -1; WK="J6K5
try{ *^([ ~[
oSavedFile.write(b,nStart,nLen); ',GS#~
n = nLen; 4t)%<4
} Q}S_%I}u:
catch(IOException e) }(egMx;"3J
{ k</%YKk
e.printStackTrace (); s?ko?qN(
} $T :un.TM
-l%J/:
|+`c3*PV
return n; ~rjTF!
} 5OoN!TEM
z>w`ZD}XY
N)&4Hy
} CRbdAqofV
fX jG5Tv
ho>k$s?
/* QdLYCR4f
**SiteInfoBean.java 5e sQ;
*/ *xp\4;B
package NetFox; iS5W>1]
kD bhu^~B
hDV20&hq
public class SiteInfoBean { :>itXD!
"zIFxDR#
%F kMv
private String sSiteURL; //Site's URL v\`9;QV5
private String sFilePath; //Saved File's Path 1 { , F
private String sFileName; //Saved File's Name J[^}u_z
private int nSplitter; //Count of Splited Downloading File "_2Ng<2
:ujCr.
TNQP"9[?
public SiteInfoBean() s}pIk.4ot!
{//nSplitter的缺省值为5 5MzFUv0)
//default value of nSplitter is 5 uUKcB:
this("","","",5); V21njRS
} YDGS}~m~Q
IF]lHB
Cuc$3l(%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Agrp(i"\@
{ OLI$1d_
sSiteURL= sURL; eHDef
sFilePath = sPath; hK<5KZ/4
sFileName = sName; QJ|ap4r
this.nSplitter = nSpiltter; e)E$}4
+nQw?'9Z
^!q?vo\j|
} z"*/mP2
7z~_/mAI
r[?1
public String getSSiteURL() h[Gg}N!
{ \P1=5rP
return sSiteURL; Dde]I_f}
} M4xi1M#%
N25V]
;;A2!w{}[i
public void setSSiteURL(String value) 97)/"i e
{ m[k_>e\u
sSiteURL = value; Kt0(gQOr0
} ?'"X"@r5
7mm1P9Z
f-nz{U
public String getSFilePath() .k[o$z\EkF
{ .5!t:FPOv
return sFilePath; gl).cIpw
} <w\:<5e'
0|; .6\
K!,<7[MBg
public void setSFilePath(String value) l|5fE1K9U
{ (@WA1oNG
sFilePath = value; NAPX_B,6
} :6q]F<oK
>[6{LAe~hp
?bw4~
public String getSFileName() KR"M/#
{ Xv@SxS-5l
return sFileName; L4L2O7
} r]ShZBAbYp
U.{l;EL:T
Ma|qHg
public void setSFileName(String value) I}2P>)K
{ P9T5L<5
sFileName = value; .Yw'oYnS
} F]O$(7*
ZtHm\VTS
lD{Aa!\
public int getNSplitter() 1wW)tNKIF
{ [=%TnT+^9
return nSplitter; _20#2i&
} vy,&N^P
$)H@|<K
;60.l!
public void setNSplitter(int nCount) R/`q/0T.
{ Y wkyq>Rv
nSplitter = nCount; p\{-t84n
} bqQq=SO
} OCy0#aPRS
BnRN;bu
E\m5%bK\B
/* M,}|tsL
**Utility.java c]B$i*t
*/ -YD+(c`l
package NetFox; N8`?t5
Z0De!?ALV\
XlI!{qj|
public class Utility { R}mn*h6
8>/Q1(q0
#P#-xz
public Utility() 1 y}2+Kk
{ ! Q<>3xZ
8.bKb<y
m?HZ;
} 7=]i~7uy
flgRpXt
//线程睡眠 +\Q?w?DE|
public static void sleep(int nSecond) m*X[ Jtr
{ <}6{{&mT4
try{ Jgu94.;5
Thread.sleep(nSecond); 1c+]gIe
} {YUIMd!Y
catch(Exception e) !EQ@#qW/
{ 3sCFHn#c
e.printStackTrace (); 5X.e*;
} fJZp?e"
} 0b91y3R+
(Toq^+`c
//日志 e"r)R8
public static void log(String sMsg) wB>r(xQ'
{ L!_ZY
System.err.println(sMsg); ;v
} jEXW
DP/J(>eG
$hxNhI
public static void log(int sMsg) #E0t?:t5bk
{ V0nn4dVO
System.err.println(sMsg); 2k6 X,
} OdI\B
} Hx$c N
htY=w}>
C6_@\&OA
/* .k4W_9
**TestMethod.java `bKA+c,f
*/ e4OeoQ@ >
package NetFox; _ .i3,-l)
;d$qc<2uA
VGL#!4wK
public class TestMethod { ~"Gf<3^y+
]\RRqLDzkg
FZiW|G
public TestMethod() A|}l)!%
{ ///xx/weblogic60b2_win.exe )Z+{|^`kJ
try{ 2}?wYI*:5|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); I &*_,d
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); YJxw 'U >P
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ff^@~X+W<
fileFetch.start(); p#f+P?
} ;DnUQj
catch(Exception e){e.printStackTrace ();} G= ^X1+_
+*oS((0s
d+iR/Ssc
} e7u^mJ
ZV}X'qGaq
_B2V "p
public static void main(String[] args) >*twTlb{
{ #sKWd
new TestMethod(); m"c :"I6
} TaJB4zB
} 2S`?hxAL
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