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)); !T1)tGrH
} !z?;L_Lb
for(int i=0;i<nEndPos.length-1;i++) =l1O9/\9
{ O"f|gc)GLz
nEndPos = nStartPos[i+1]; THz=_L6
} IW- BY =C
nEndPos[nEndPos.length-1] = nFileLength; 1n EW'F
} ~\[\S!"
} Dt]*M_
2[Vs@X
^26}8vt
//启动子线程 btv.M
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; v>p}f"$`
for(int i=0;i<nStartPos.length;i++) 17@#"uT0
{ 5/4q}U3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *)um^O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), QHbjZJ N
nStartPos,nEndPos,i); AOR(1Qyo
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p$zj2W+sN
fileSplitterFetch.start(); S'%!KGVe
} R^tDL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VT5o#NR{R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); uI+^8-HZ;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", IjnO2X
nEndPos = " + nFileLength); Qj(|uGqm3
// fileSplitterFetch[nPos.length-1].start(); FAF+}
lb[\Lzdvmu
W5zlU2
//等待子线程结束 UN7J6$!Cx7
//int count = 0; ^HI}bS1+|
//是否结束while循环 wsyAq'%L
boolean breakWhile = false; b%D}mxbS
qn#f:xltu
l]KxUkA+
while(!bStop) -`} d@x
{ Kf'oXCs
write_nPos(); J?84WS
Utility.sleep(500); `HJRXoLySW
breakWhile = true; 9zD^4j7
Sz'JOBp
,[|4{qli\
for(int i=0;i<nStartPos.length;i++) dEWI8Q]
{ I-o|~
if(!fileSplitterFetch.bDownOver) ylBjuD+
{ i9quP"<9
breakWhile = false; J#jx)K!
break; &/tGT3)
} I+_u?R)$
} } 2P,Z6L
if(breakWhile) 2]/[
break; !i*bb~
OAd}#R\U
(| X?
//count++; )|CF)T-
//if(count>4) kSH|+K\M4
// siteStop(); ?(P3ZTk?.
} :igURr
V j"B/@
;PF!=8dW
System.err.println("文件下载结束！"); KI~M.2pk
} n0<I
catch(Exception e){e.printStackTrace ();} K!BS?n;
} >r~!'Pd!
Gs)2HR@>
`]3A#y)v
//获得文件长度 mQy!*0y
public long getFileSize() Y> f 6
{ 1*ui|fuK
int nFileLength = -1; <zhN7="
try{ k^v P|*eu
URL url = new URL(siteInfoBean.getSSiteURL()); Mo_(WSs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "0#d F:qt
httpConnection.setRequestProperty("User-Agent","NetFox"); H:>i:\J/M9
1.y|bB+kB
K`#bLCXEV0
int responseCode=httpConnection.getResponseCode(); :{ Q[kYj
if(responseCode>=400) f*&4d
{ MW$ X4<*KD
processErrorCode(responseCode); UgjY
return -2; //-2 represent access is error d1=fA%pJ
} WwBs_OMc
z~y=(T
'k?*?XxG
String sHeader; o9#8q_D9
R@Kzdeo
2%*mL98WK
for(int i=1;;i++) YqSkz|o}m
{ Y6r<+#V
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); x=~$ik++
//Utility.log(in.readLine()); '#p2v'A
sHeader=httpConnection.getHeaderFieldKey(i); 7lYiufg
if(sHeader!=null) G>yTv`-
{ >^q7:x\
if(sHeader.equals("Content-Length")) 0281"aO
{ c-gpO|4>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); POtwT">z
break; 6o!Y^^/U
} }:2GD0Ru
} rS^+y{7
else ]E!b&
break; ytg' {)
} c mI&R(
} uF89B-t
catch(IOException e){e.printStackTrace ();} 236,o {9e
catch(Exception e){e.printStackTrace ();} TowRY=#jiS
! >l)*jN8
V$';B=M
Utility.log(nFileLength); ir/-zp_
MX\v2["FoV
zv}3Sl@
return nFileLength; 3}lT"K
} F vt5vQ
;+-M+9"?O
:$J4T;/{
//保存下载信息（文件指针位置） "{F e
private void write_nPos() Oj~4uT&"
{ MhXJ /bup
try{ +#a_Y
output = new DataOutputStream(new FileOutputStream(tmpFile)); \Q m1+tg
output.writeInt(nStartPos.length); />,KWHR|:
for(int i=0;i<nStartPos.length;i++) 9yt)9f
{ PBo;lg`
// output.writeLong(nPos); oYn|>`+6:y
output.writeLong(fileSplitterFetch.nStartPos); oPCtLz}z
output.writeLong(fileSplitterFetch.nEndPos); x'IYWo ]
} (_aM26s
output.close(); gJUawK
} ndCHWhi
catch(IOException e){e.printStackTrace ();} &W@#pG
catch(Exception e){e.printStackTrace ();} WMw^zq?hd@
} Nxd<#p
{ *&Wc Os
y.PsC '
//读取保存的下载信息（文件指针位置） rE[:j2HF
private void read_nPos() n?=d)[]
{ B{ptP4As-
try{ VwKo)zH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); rMy(NAo_
int nCount = input.readInt(); zs<2Ozv
nStartPos = new long[nCount]; d=v{3*a_4,
nEndPos = new long[nCount]; =Mby;wQ?|
for(int i=0;i<nStartPos.length;i++) ;Or]x?-
{ 8'}D/4MUr
nStartPos = input.readLong(); pDloew
nEndPos = input.readLong(); ,6iXlch
} Je1'0h9d
input.close(); f%2>pQTq@)
} xh) h#p.
catch(IOException e){e.printStackTrace ();} nB .?=eUa
catch(Exception e){e.printStackTrace ();} <bbC&O\
} z +NwGVk3
UcI;(Va
b|'{f?
private void processErrorCode(int nErrorCode) ,K>q{H^
{ 4[o/p8*/
System.err.println("Error Code : " + nErrorCode); cU
} c?H@HoF
6myF! H=
(n+FEE<
//停止文件下载 @3_[NI%
public void siteStop() jMV9r-{*+
{ -Y=o
bStop = true; Qf:#{~/
for(int i=0;i<nStartPos.length;i++) #i1z&b#@
fileSplitterFetch.splitterStop(); yy(.|
a2!;$B%
P1>?crw
} &4R-5i2a
} ]QJWqY
//负责部分文件的抓取 ![l`@NH[U
**FileSplitterFetch.java 2C59fXfd
*/ vkgAI<
package NetFox; q0y#Y
Fk*C8
KW 78J~u+
import java.io.*; u4QBD5T"
import java.net.*; dum(T
(l]_0-Z
zS<idy F`
public class FileSplitterFetch extends Thread { px>g
#x|IEjoa
7~2c"WE
String sURL; //File URL .FWi$B';
long nStartPos; //File Snippet Start Position 5%K(tRc|
long nEndPos; //File Snippet End Position ucwUeRw,
int nThreadID; //Thread's ID JMVh\($,x
boolean bDownOver = false; //Downing is over ]qPrXuS/
boolean bStop = false; //Stop identical p.@_3^#|
FileAccessI fileAccessI = null; //File Access interface ["7]EW\!:
>)6d~
id:6O+\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException iR39lOr
{ \>N"{T
this.sURL = sURL; L2}p<?f
this.nStartPos = nStart; n{8v^x
this.nEndPos = nEnd; _p^&]eQ+k#
nThreadID = id; agUdPl$e\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \{K~x@`
} ^9`S`Bhp
9tBE=L=
(D~NW*,9
public void run() <Dq7^,}#
{ {wwkbc*
while(nStartPos < nEndPos && !bStop) 9>7w1G#
{ t}x^*I$*
mVVL[z2+
sOb=+u$$9
try{ m(rd\3d
URL url = new URL(sURL); &++tp5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FL?Ndy"I
httpConnection.setRequestProperty("User-Agent","NetFox"); h4geoC_W2
String sProperty = "bytes="+nStartPos+"-"; G+V?c1Me
httpConnection.setRequestProperty("RANGE",sProperty); :211T&B%A_
Utility.log(sProperty); 5JggU
+ )lkHv$R
DNmP>~
InputStream input = httpConnection.getInputStream(); (*Fb/
//logResponseHead(httpConnection); 2'T uS?
\_|g}&}6Y
*DS>#x@3*i
byte[] b = new byte[1024]; 8Luw<Q
int nRead; ,WgEl4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) qx2M"uFJ
{ R Y ";SfYb
nStartPos += fileAccessI.write(b,0,nRead); 8;GuJP\
//if(nThreadID == 1) B82SAV/O
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j~C-T%kYa
} Zy&?.d[z
8h'*[-]70u
Q8?:L<A
Utility.log("Thread " + nThreadID + " is over!"); dSPye z
bDownOver = true; 7AuzGA0y
//nPos = fileAccessI.write (b,0,nRead); 1%Su~Z"W>
} |Q*OA
catch(Exception e){e.printStackTrace ();} HBiUp$(mB
} nz_1Fu>g|
} >(BAIjF E\
:/~TV
CEEAyip-c
//打印回应的头信息 Qf.]Mw?Bm
public void logResponseHead(HttpURLConnection con) 3#Qek2
{ p|RFpn2ygF
for(int i=1;;i++) \wM8I-f!
{ fA" VLQE
String header=con.getHeaderFieldKey(i); -v &
if(header!=null) |@Sj:^cJD
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l0nm>ps'D
Utility.log(header+" : "+con.getHeaderField(header)); _,bDv`>Ra
else C<yjGtVD
break; G^&P'*
} ?CSv;:
} #Zj3SfU~`
.ovG_O
"?r_A*U
public void splitterStop() \?~cJMN
{ t~kh?u].j
bStop = true; 'H8;(Rw
} u)9YRMl
716r/@y$6
/M5R<rl
} C|-QU
^j *H
wS @-EcCB
/* Cu`ty] -'
**FileAccess.java GB8>R
*//文件访问(定位，写) Y@2v/O,\
package NetFox; ;Yu|LaI\<m
import java.io.*; ,ocAB;K
i>{.Y};
RZbiiMC>
public class FileAccessI implements Serializable{ 1;"DIsz@d
zY2o;-d|4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cg).b?g
RandomAccessFile oSavedFile; &at>sQ'
long nPos; ]%eyrbU
%[WOQ.Sh
Y0xn}:%K
public FileAccessI() throws IOException SI9PgC
{ ]CGH )4Pe
this("",0); <gu>06
} mJ JF
K %.>o
XkEE55#>|
public FileAccessI(String sName,long nPos) throws IOException jSdW?IH
{ 3F?_{A
oSavedFile = new RandomAccessFile(sName,"rw"); iCNJ%AZH
this.nPos = nPos; I~)A!vp
oSavedFile.seek(nPos); n#"N"6s
} PsO>&Te2
3e ?J#;
g66x;2Q
public synchronized int write(byte[] b,int nStart,int nLen) EWK?vs
{ P\{}yd
int n = -1; 8[L]w^
try{ q"Th\? }%
oSavedFile.write(b,nStart,nLen); 6L,"gF<n
n = nLen; s7"5NU-
} Y_,Tm
catch(IOException e) d]+2rt}]hL
{ z6uHe{|
e.printStackTrace (); ;&`6b:ug
} PaZd^0'!Z
MoC@n+Q+@
>TG#
return n; -fT}Nj\
} 7_CX6:
5 [X,?
P 9?I]a)G
} -muP.h/
I/)*pzt8
N?><%fra
/* ~'VVCtA
**SiteInfoBean.java gPcOm b
*/ gVI T6"/
package NetFox; ^a?g~G
X]c>clk,
~*hCTqHvN
public class SiteInfoBean { r:--DKt
Ls/*&u
|u_fVQj
private String sSiteURL; //Site's URL d5#z\E??
private String sFilePath; //Saved File's Path XVzsqi*Z
private String sFileName; //Saved File's Name 3T~DeqAyw
private int nSplitter; //Count of Splited Downloading File K96N{"{iI%
_3zJ.%
Iwe
public SiteInfoBean() i0'g$
{//nSplitter的缺省值为5 F!zGk(Pu
//default value of nSplitter is 5 =k##*%
this("","","",5); {Lugdf'
} ?eDZ-u9)
&EJ/Rl
z C7b
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7}puj%JS /
{ tu6<>
sSiteURL= sURL; <6.?:Jj
sFilePath = sPath; y/;DA=
sFileName = sName; 3*#$:waGd
this.nSplitter = nSpiltter; "1%\Fil
}%`f%/
V?"1&m&E
} TTD#ovo'
w}0rDWuR[
@YbZ"Jb
public String getSSiteURL() @nOuFX4
{ 2[i(XG{/
return sSiteURL; (&Mv!6]
} K)GpQ|4:<
?^WX]SAl
5V8`-yO9
public void setSSiteURL(String value) cp2a @
{ *0x!C8*`Xe
sSiteURL = value; =55V<VI
} J+l#!gk$!
&Xh=bM'/%m
uTNy{RBD+
public String getSFilePath() uoTc c|Kc
{ A9y@v{txN
return sFilePath; ]sJjV A
} Uj^Y\w-@Z
j+[oZfH
|}Mthj9n
public void setSFilePath(String value) ^+x,211f
{ ]-jaIvM
sFilePath = value; 5?*Iaw
} 4@=[rZb9
P5__[aTD
00pe4^U
public String getSFileName() x\8gb#8
{ zQoJ8i>
return sFileName; R~BFZF>:
} _7<G6q2(
<K <|G
<SiJA`(7
public void setSFileName(String value) )i[K1$x2
{ F&HvSt}l5
sFileName = value; _mTNK^gB
} `2`h4[^ [X
# blh9.V&F
pV*d"~T
public int getNSplitter() @ 1FWBH~
{ jQ['f\R
return nSplitter; [nLd>2P
} `KUL4) g~
g ,yB^^%
GW2v&Ul7(
public void setNSplitter(int nCount) K~+x@O*
{ A>6_h1
nSplitter = nCount; Awe'MGp%
} x\pygzQ/
} :=\`P
d?><+!a
?f*>=;7=
/* j-v/;7s/B
**Utility.java Sg1,9[pb
*/ m}t`43}QE
package NetFox; rEoOv
p1s|JI
q#`;G,rs
public class Utility { |#EI(W?`
B-V
4KY@y?H g
public Utility() e?WI=Og
{ P_(<?0l
{6iHUK
n1)].`
} 0>:`|IGnT2
NN~PWy1opa
//线程睡眠 $'KhA6u
public static void sleep(int nSecond) ~R7{gCqdr
{ $E^*^({
try{ FYH^axpp
Thread.sleep(nSecond); ;Bat--K7+
} [Vj|fy4
catch(Exception e) SDO~g~NTp
{ +'aG{/J
e.printStackTrace (); mV}eMw
} L08"8\
} n6{nx[%7N7
BRtT 7
//日志 xLw[ aYy4
public static void log(String sMsg) eNrwkV^
{ c+jnQM'
System.err.println(sMsg); i}>}%l|
} Oyp)Wm;@
|`Be(
%3T:W\h
public static void log(int sMsg) GuQ#
{ yn04[PN2
System.err.println(sMsg); jR{t=da
} wV'_{/WM
} =<U'Jtu6'
j2jUrl
JB HnJm
/* r6L
**TestMethod.java !%QbE[Kl>
*/ Tx/KL%X
package NetFox; s"l ^v5
F>at^6^
]CgZt'h{
public class TestMethod { :U-yO 9!j
uN6xOq/
uR82},r$m
public TestMethod() to)Pl}9QkK
{ ///xx/weblogic60b2_win.exe &sGLm~m#
try{ Zk0?=f?j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); h|ja67VG
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); y|YhDO
SiteFileFetch fileFetch = new SiteFileFetch(bean); =GLMdhD]
fileFetch.start(); `(8RK
} uQkQ#'e|
catch(Exception e){e.printStackTrace ();} ,J'@e+jV
qb5IpI{U
o Hrx$>W]
} 4<U6jB5
@fd{5 >\
F=yE>[! LB
public static void main(String[] args) ~PCS_
{ T7Yg^ -"
new TestMethod(); E5$uvxCI
} ;MjOs&1f0K
} fwaM;YN_
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