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)); /N(L52mz
} diN5*CF'~
for(int i=0;i<nEndPos.length-1;i++) _ h\wH;
{ Xao 0cb.R
nEndPos = nStartPos[i+1]; s>Xx:h6m
} {'P7D4w
nEndPos[nEndPos.length-1] = nFileLength; H: q(T >/w
} dE9xan
} N9IBw',
_ Js& _d
FaO=<jYi
//启动子线程 HVG9 C$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2@WF]*Z
for(int i=0;i<nStartPos.length;i++) `h+ia/
{ wlr/zquAE9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R:HF~}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), cd,)GF
nStartPos,nEndPos,i); s\g"~2+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gd3~R+Kd
fileSplitterFetch.start(); `ro~l_U;A
} rxtp?|v9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r<4FF=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +BcJHNIB
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", v#i,pBj
nEndPos = " + nFileLength); dX|(n.}
// fileSplitterFetch[nPos.length-1].start(); d7Lna^
iW\cLp "
h;105$E1
//等待子线程结束 q]+'{Ci@
//int count = 0; ;~Y0H9`
//是否结束while循环 tM3eB= .*
boolean breakWhile = false; 3}{od$3G
Ig*68M<
3>%oGbo
while(!bStop) 4kZX$ct}
{ Z^w11}
write_nPos(); U6V+jD}L]
Utility.sleep(500); ``bIqY
breakWhile = true; 9A0wiKp
)=6|G^
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for(int i=0;i<nStartPos.length;i++) P+00wbx0
{ #=r:;,,
if(!fileSplitterFetch.bDownOver) "bZ{W(h
{ qzq_3^66
breakWhile = false; #T_m|LN7
break; B ^>}M
} '?Fw]z1$
} K4938 v
if(breakWhile) -Bymt[
break; 2uw1R;zw
9&e=s<6dO
{,z$*nf
//count++; 3dm lP2
//if(count>4) ;`<uo$R
// siteStop(); ir^%9amh
} Dj!v+<b
CjRI!}S
[]R`h*#
System.err.println("文件下载结束！"); Yg_;Eu0'?
} tNf?pV77
catch(Exception e){e.printStackTrace ();} f S-(Kmh
} >D20f<w(H
c\.Hs9T >
T;/Y/Fd
//获得文件长度 ?`R;ZT)U-
public long getFileSize() LJ7Qwh_",
{ 3D<s#
int nFileLength = -1; dd4g?):
try{ #P[d?pY
URL url = new URL(siteInfoBean.getSSiteURL()); oJ}!qrrH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Qu4Bd|`(k
httpConnection.setRequestProperty("User-Agent","NetFox"); et[n;nl>V
6`(x)Q9
w6ZyMR,T
int responseCode=httpConnection.getResponseCode(); := OdjfhY
if(responseCode>=400) &~`Ay4hq
{ [|{2&830
processErrorCode(responseCode); nk8jXZ"w
return -2; //-2 represent access is error ,CACQhrng
} r9:Cq
Y"J' 'K
q)S70M_1
String sHeader; x;d*?69f]
UuDs
[k)xn3[
for(int i=1;;i++) $-4OveS~B
{ v5J% p4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); C>\0 "}iD
//Utility.log(in.readLine()); h>>KH*dQ
sHeader=httpConnection.getHeaderFieldKey(i); ]:Y@pZ
if(sHeader!=null) (.6~t<DRv
{ a "*DJ&
if(sHeader.equals("Content-Length")) |8,|>EyqK
{ J,@SSmJ`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "[W${q+0x
break; s^:8bFn9$
} vU5a`0mH
} vFuf{ @P
else Z)=S. )
break; ')!+>b(P
} F$[1KjS
} 2flgfB}2k
catch(IOException e){e.printStackTrace ();} pO^gooV\
catch(Exception e){e.printStackTrace ();} b|7c]l
~loJYq'y
{Dv^j#
Utility.log(nFileLength); 5LJUD>f9Z
'9O4$s1
u~kfz*hz
return nFileLength; (sX=#<B%
} & w%%{lM
RY8Ot2DWi
46U?aHKW@|
//保存下载信息（文件指针位置） "Me)'
private void write_nPos() k 4|*t}o7
{ Snm m(.
try{ R.KqTEs<k
output = new DataOutputStream(new FileOutputStream(tmpFile)); <zmtVE*>g
output.writeInt(nStartPos.length); 0#K?SuY.eN
for(int i=0;i<nStartPos.length;i++) ;%u'w;sgq
{ +C`h*%BW
// output.writeLong(nPos); Grot3a
output.writeLong(fileSplitterFetch.nStartPos); :-Gf GL>]
output.writeLong(fileSplitterFetch.nEndPos); a;},y|'E
} 879x(JII
output.close(); O0|**Km\+
} :Bk!YK
catch(IOException e){e.printStackTrace ();} )C \ %R
catch(Exception e){e.printStackTrace ();} %Pl 7FHfB
} l5?fF6#j
;=.i+
J$Huzs#
//读取保存的下载信息（文件指针位置） pVuJ4+`
private void read_nPos() #9HQW:On
{ s06tCwPp
try{ 3_%lN4sz
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Z^P]-CB|6A
int nCount = input.readInt(); :wlX`YW+e
nStartPos = new long[nCount]; v4X\LsOP
nEndPos = new long[nCount]; ZHA6BVVT
for(int i=0;i<nStartPos.length;i++) .QwwGm
{ "rnZ<A}
nStartPos = input.readLong(); y,I?3p|S
nEndPos = input.readLong(); D%PrwfR
} r&^LSTU0!
input.close(); &c;@u?:@S
} +o{]0~y
catch(IOException e){e.printStackTrace ();} CYIp 3D'k
catch(Exception e){e.printStackTrace ();} bf~gWzA
} m(~5X0
x6=Yt{
;QMRm<CLV
private void processErrorCode(int nErrorCode) Gp}:U>V)
{ [A@K)A$f
System.err.println("Error Code : " + nErrorCode); 8|:bis~wm
} )(&Z&2~A
/qf2LO'+
f>g<:.k*
//停止文件下载 4Ji6B)B
public void siteStop() ym>>5(bni
{ XaFu(Xu7
bStop = true; cP >MsUZWl
for(int i=0;i<nStartPos.length;i++) )s @}|`
fileSplitterFetch.splitterStop(); ~g&FeMo
-!X,MDO
T6 K?Xr{_
} os=Pr{
} -,;r %7T
//负责部分文件的抓取 Oa[G #
**FileSplitterFetch.java U g'y
*/ wi{qN___
package NetFox; [^iQE
6\8 lx|w
E=Z;T
import java.io.*; P!;%DI!<b
import java.net.*; SV-M8Im73z
ROWb:tX}
_RzwE$+9
public class FileSplitterFetch extends Thread { $UgQ1Qc
2(_+PQ6C=
RR*eq.;
String sURL; //File URL @-uV6X8|
long nStartPos; //File Snippet Start Position sbWen?
long nEndPos; //File Snippet End Position BvXA9YQ3
int nThreadID; //Thread's ID |AY`OVgcKD
boolean bDownOver = false; //Downing is over C26vH#C
boolean bStop = false; //Stop identical NGA8JV/U
FileAccessI fileAccessI = null; //File Access interface }sbh|#
V$D+Joj
K^H{B& b8
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =Gka;,n
{ _;o)MTw|'
this.sURL = sURL; ccLTA
this.nStartPos = nStart; QKj8~l(
this.nEndPos = nEnd; dNQR<v\IL
nThreadID = id; D..dGh.MY
fileAccessI = new FileAccessI(sName,nStartPos);//定位 '\vmm>
} fjc8@S5x9j
\KBE+yj
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public void run() i_ha^mq3
{ ,\HZIl[8
while(nStartPos < nEndPos && !bStop) J$9`[^pV
{ ^A4bsoW
Ro&s\T+d
4$j7DJ8dj
try{ v[3QI7E3
URL url = new URL(sURL); zz4TJ('
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z*9Qeu-N:
httpConnection.setRequestProperty("User-Agent","NetFox"); H9@24NFb
String sProperty = "bytes="+nStartPos+"-"; m :6.
httpConnection.setRequestProperty("RANGE",sProperty); J(k\Pz*
Utility.log(sProperty); ?`m#Y&Oi
<ptskbu
l%$~X0%DM
InputStream input = httpConnection.getInputStream(); xq U@87[_
//logResponseHead(httpConnection); {FIr|R&
cqP)1V]
~OuKewr\
byte[] b = new byte[1024]; 0^5*@vt
int nRead; 75u5zD
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4Nz@s^9
{ -?m"+mUP
nStartPos += fileAccessI.write(b,0,nRead); : h"Bf@3
//if(nThreadID == 1) {8!\aYI
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R2]2#3`
} jH4,-
Hr?_`:
/< OoZf+[
Utility.log("Thread " + nThreadID + " is over!"); aP#nK
bDownOver = true; k9V#=,K0
//nPos = fileAccessI.write (b,0,nRead); K,ccM[hu|
} 8'niew 5d
catch(Exception e){e.printStackTrace ();} +3;`4bW
} cip"9|"
} {LwV&u(
K *<+K<Tp
*%[L @WF
//打印回应的头信息 2X:OS/
public void logResponseHead(HttpURLConnection con) -y@# ^SrJ
{ 4pYscB
for(int i=1;;i++) %K9 9_Cl3
{ ;9WS#>o
String header=con.getHeaderFieldKey(i); _TGv"c@V
if(header!=null) _LVi}mM
//responseHeaders.put(header,httpConnection.getHeaderField(header)); TzPG(f
Utility.log(header+" : "+con.getHeaderField(header)); 8ZnHp~
else nfL-E:n=
break; *OX;ZQg0
} "@P)
} m1d*Lt>F@
Kd<c'!
"[Z'n9C
public void splitterStop() )<<}8Fs
{ i4Ps#R_wx
bStop = true; /Dmuvb|A
} lk<}`#(g
W7\s=t\
ji8)/
} ~8A !..Z
^ UB*Q
Ct8}jg"
/* I%8>nMTJ
**FileAccess.java ;,OZ8g)LH
*//文件访问(定位，写) w=|"{-ijo
package NetFox; aMLtZ7i>
import java.io.*; Vr|sRvz
li4"|T&
2^V/>|W>w
public class FileAccessI implements Serializable{ Cyn_UE
@4ccZ&`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B1u.aa$
RandomAccessFile oSavedFile; "DpgX8lG_
long nPos; D^\gU-8M
<w9<G
ZQ MK1
public FileAccessI() throws IOException p+ki1!Ed
{ .huk>
this("",0); F\)?Ntj)>@
} -45xa$vv
5[qCH(6
(^U 8wit/
public FileAccessI(String sName,long nPos) throws IOException OG!+p}yD]
{ W%&[gDp
oSavedFile = new RandomAccessFile(sName,"rw"); t,v=~LE
this.nPos = nPos; x%$as;
oSavedFile.seek(nPos); 4ayZ.`aK
} )<>1Q{j@
EN\ uX!
(mR;MC
public synchronized int write(byte[] b,int nStart,int nLen) DJ]GM|?
{ 5N5Deb#V
int n = -1; #rps2nf.j
try{ v}>5!*
oSavedFile.write(b,nStart,nLen); I<&(Dg|XQ
n = nLen; [VL+X^
} ]"T1clZKd(
catch(IOException e) u A=x~-I
{ V 5
e.printStackTrace (); K+F]a]kld
} :JI&ngWK
fRow@DI\
i& phko}
return n; 1dE|q{
} asLvJ{d8s
Iu=n$H
HOPi2nf{
} @`D`u16]i
7hq$vI%0
xDtJ&6uFw
/* T`Jj$Lue{
**SiteInfoBean.java $z":E(oy
*/ #]MV
package NetFox; Y!0ZwwW
k04CSzE"%
eGEeWJ}[$
public class SiteInfoBean { M{
1P '_EJ]M
UbDRE[^P
private String sSiteURL; //Site's URL $HE ?B{
private String sFilePath; //Saved File's Path %1jlXa
private String sFileName; //Saved File's Name gA/8Df\G:l
private int nSplitter; //Count of Splited Downloading File xUw)mUn@N
-Y:^<C^^&8
Mu>WS)1lS
public SiteInfoBean() 2 yY.rs
{//nSplitter的缺省值为5 0;6^fiSY;
//default value of nSplitter is 5 uY"Bgz:=d
this("","","",5); aEJds}eE6)
} nUy2)CL[L
0+P[0
4!,`|W1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c c^I9g~
{ U5f<4I
sSiteURL= sURL; ^~65M/
sFilePath = sPath; S(Ej: H
sFileName = sName; ,!{/Y7PmJ
this.nSplitter = nSpiltter; $Lf-Gi
rT}k[
@x4IxGlUs
} D?Y j5eOa
A]WR-0Z7
;H%T5$:trP
public String getSSiteURL() z~R:!O-
{ -sqoE*K[8
return sSiteURL; UwQyAD]Ht
} jykY8;4
8t$w/#'@
qEW3k),
public void setSSiteURL(String value) :~gG]|F
{ _=s{,t &u
sSiteURL = value; ^|+;~3<J
} 12bt\h9
hZ;[}5T\<S
B+w< 0No
public String getSFilePath() x*}*0).
{ omEnIfQSO
return sFilePath; 5kju{2`GF
} 99]&Xj
CKau\N7T
k5X& |L/
public void setSFilePath(String value) Jd0I!L
{ MRn;D|Q
sFilePath = value; D3MRRv#
} }0(.HMiGj
h,u?3}Knnb
zwEZ?m!
public String getSFileName() +_E\Omcw
{ }-8ZSWog6f
return sFileName; WXgGB[x
} 9}_ccq
Bf-KCqC".
4a6WQVS
public void setSFileName(String value) G&?,L:^t
{ NZh\{!
sFileName = value; $^XCI%DH
} ?~_[/
b+rn:R
c|,6(4j>$
public int getNSplitter() x6BO%1
{ Xu+^41
return nSplitter; JJ=%\j
} Z91GM1lrf8
p+pBk$4
`ywI+^b
public void setNSplitter(int nCount) / ~\ I
{ =8!FY"c*
nSplitter = nCount; },W<1*|
} 0zCmU)ng
} 8qi6>}A
%0<-5&GE
$afE= qC*
/* 8M DX()Bm
**Utility.java *sPG,6>
*/ c%bGVRhE
package NetFox; ;vDjd2@
w '<8lw
mTsl"A>
public class Utility { EG|fGkv"
8FmRD
BnL[C:|
public Utility() cp&- 6 w+
{ hj_%'kk-A
|~y>R#u8pm
"iC*Eoz#.
} Zc<fopih
S=R}#
//线程睡眠 F.%g_Xvk:
public static void sleep(int nSecond) c2aW4TX2
{ .-[d6Pnw
try{ ha%3%O8Z
Thread.sleep(nSecond); mK>c+ u)
} +F9)+wT~;q
catch(Exception e) V:wx@9m)
{ Bn5O;I13
e.printStackTrace (); \en}8r9cy
} dg?[gD8!4&
} N!u(G
iLyJ7zby
//日志 A{3?G-]*
public static void log(String sMsg) juAUeGT
{ _W3>Km-A=/
System.err.println(sMsg); -ST[!W V
} Y5Ub[o
c~0hu*&
r/32pY
public static void log(int sMsg) J!5>8I(_wX
{ 8)1k>=
System.err.println(sMsg); (1|_Nr
} xD#r5
} ;ZSJ-r
9MmAoLm
*&m{)cTs
/* '|9fDzW"]
**TestMethod.java rerl-T<3
*/ S\F;b{S1
package NetFox; e{~3&
n&`=.[+A
C_RxJWka
public class TestMethod { **%/Ke[
k6pXc<]8
vwlPFrLl
public TestMethod() dCF!.
{ ///xx/weblogic60b2_win.exe xP3v65Q1
try{ _I&];WM\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); y7s:Buyc
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p7\}X.L
SiteFileFetch fileFetch = new SiteFileFetch(bean); W6d[v/+K+
fileFetch.start(); {5$.:Y
} U1Z.#ETnM
catch(Exception e){e.printStackTrace ();} RO]Vn]qb
\R6D'Yt
8w:A""
} 4^KeA".
K_fQFuj+
[|XMR=\>
public static void main(String[] args) ?_!} lg
{ ;Tn$c70
new TestMethod(); +;H-0Q5
} G<S(P@ss
} RoG `U
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