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)); }d iE'
} %L7DC`
for(int i=0;i<nEndPos.length-1;i++) lN{>.q@V`r
{ +aPe)U<t
nEndPos = nStartPos[i+1]; N'$P( bx
} P4c3kO0
nEndPos[nEndPos.length-1] = nFileLength; UvB\kIH
} ]#rV]As
} E}a.qM'
OYn5k6
RL/7>YQ
//启动子线程 ua &uR7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1/qD5 *`Y
for(int i=0;i<nStartPos.length;i++) 8ph1xQ'
{ jVN=_Y}\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d(R8^v/L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -vk/z+-^!
nStartPos,nEndPos,i); ,# .12Q!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JP {`^c
fileSplitterFetch.start(); KxeqQ@
} 6c/0OM#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Cw kQhj?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); LTH,a?lD
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", X*d!A >s
nEndPos = " + nFileLength); dnXu(e%
// fileSplitterFetch[nPos.length-1].start(); x_?K6[G&}
~i'!;'-_}
="%887e
//等待子线程结束 "&^KnWk=
//int count = 0; u|u)8;'9(
//是否结束while循环 _v,Wl/YAp
boolean breakWhile = false; T g3MPa#g
$AMcU5^b7
M(C}2.20
while(!bStop) )`\Q/TMl5
{ G{Ju2HY
write_nPos(); 0Q,Tcj
Utility.sleep(500); gSyBoY
breakWhile = true; 0/fZDQH
v$(Z}Hg
[Fk|m1i!
for(int i=0;i<nStartPos.length;i++) B4+u/hkbh?
{ /RxqFpu|.
if(!fileSplitterFetch.bDownOver) p|a`Q5z!
{ I3T;|;P7
breakWhile = false; DW:\6k
break; [eTEK W]
} o_kZ
} |Zp') JiS
if(breakWhile) |UQ[pas
break; FYefn3b
.'2I9P\!
x;~@T9.
//count++; 2e3AmR@*
//if(count>4) -ik((qx_
// siteStop(); <@+L^Ps~z
} NE)w$>0M
xCT2FvX6
d/$e#8
System.err.println("文件下载结束！"); sE|8a
} Q^l!cL| {
catch(Exception e){e.printStackTrace ();} Ah5o>ZtcO
} T-kHk(
w-v8P`V
1<lfo^B
//获得文件长度 2\+N<-(F5
public long getFileSize() 2.v`J=R
{ $M4_"!
int nFileLength = -1; 0R(['s:3`
try{ s- 0Xt<
URL url = new URL(siteInfoBean.getSSiteURL()); 9:Bn-3)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); aYHs35
httpConnection.setRequestProperty("User-Agent","NetFox"); }S13]Kk?=
1Ak0A6E
een62-`
int responseCode=httpConnection.getResponseCode(); ^(7l!
if(responseCode>=400) rd[mC[ r
{ j>v8i bS(
processErrorCode(responseCode); {CVZ7tU7]
return -2; //-2 represent access is error C$LRX7Z`o
} 'X/:TOk{W
mYXL
6!*zgA5M'
String sHeader; n%~r^C_
^U,C])n
a_b+RMy
for(int i=1;;i++) By}ZHK94I
{ %P#| }
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); N#R8ez`
//Utility.log(in.readLine()); GU Mf}y
sHeader=httpConnection.getHeaderFieldKey(i); 9]tW;?
if(sHeader!=null) M.)z;[3O
{ G2@'S&2@s
if(sHeader.equals("Content-Length")) ]<q!pE;t
{ ["ocZ? x
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `(O#$n
break; $,I@c"m{
} JEZ0O&_R
} n>SK2`
else ,,)'YhG(
break; $I ,Np)i
} P(C5@x(Z
} Tpkt'|8
catch(IOException e){e.printStackTrace ();} G#uB%:)&0u
catch(Exception e){e.printStackTrace ();} @KZW*-"
EF=5[$ u
07ppq?,y
Utility.log(nFileLength); puEu)m^
^d(gC%+!u
.O+,1&D5
return nFileLength; &/otoAr(
} _ph1( !H$
j^f54Ky.
Gs04)KJm<
//保存下载信息（文件指针位置） $h=v;1"
private void write_nPos() >I&s%4
{ 8Vt'X2
try{ {\LLiU}MJC
output = new DataOutputStream(new FileOutputStream(tmpFile)); } z7yS.{
output.writeInt(nStartPos.length); mU||(;I
for(int i=0;i<nStartPos.length;i++) f&] !;)
{ "uyr@u0b
// output.writeLong(nPos); B LZ<"npn
output.writeLong(fileSplitterFetch.nStartPos); _Vc4F_
output.writeLong(fileSplitterFetch.nEndPos); TvRm 7
} vn@sPT
output.close(); ; =*=P8&5
} Uhyf
catch(IOException e){e.printStackTrace ();} cN\_1
catch(Exception e){e.printStackTrace ();} 6W;`}'ap
} X2Q35.AB
{!.w}
O\%0D.HEz
//读取保存的下载信息（文件指针位置） v&f\ Jv7
private void read_nPos() {)Wa"|+
{ Rdj^k^V+a1
try{ 2IkyC`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }ZiJHj'<
int nCount = input.readInt(); eV;nTj
nStartPos = new long[nCount]; Q yQ[H
nEndPos = new long[nCount]; '?X?'_3
for(int i=0;i<nStartPos.length;i++) >+:cTQ|q
{ ##1/{9ywy
nStartPos = input.readLong(); MdTu722
nEndPos = input.readLong(); xz+;1JAL3
} X@)'E9g5:
input.close(); ~1S,[5u|s
} F hyY+{%
catch(IOException e){e.printStackTrace ();} p}X *HJq$
catch(Exception e){e.printStackTrace ();} 5,Co(K
} jz\>VYi(7
,bB}lU)
plNw>rFa
private void processErrorCode(int nErrorCode) YelF)Na
{ {?3i^Q=V
System.err.println("Error Code : " + nErrorCode); Vk76cV D
} N7;kWQH
rQPO+
t+0/$
//停止文件下载 '68#7Hs.
public void siteStop() Ch~y;C&e+r
{ [V5,1dmkI
bStop = true; =xb/zu(
for(int i=0;i<nStartPos.length;i++) IiX2O(*ZE
fileSplitterFetch.splitterStop(); |]Y6*uEX<
@?0))@kPc3
RE]*fRe7#
} _u~`RlA
} scrss
//负责部分文件的抓取 izu_KBzy
**FileSplitterFetch.java JX{rum
*/ 0 r;tI"
package NetFox; 2B_+5
Q}g"pl
+)_DaL E
import java.io.*; J DOs.w
import java.net.*; 4#ifm#
+.m:-^9
B!)Tytm9u
public class FileSplitterFetch extends Thread { :"Rx$;a
dw| VH1fS
98UI]? 4
String sURL; //File URL +NOq>kH@
long nStartPos; //File Snippet Start Position UyDq`@h
long nEndPos; //File Snippet End Position }5B\:*yW
int nThreadID; //Thread's ID koj*3@\p/
boolean bDownOver = false; //Downing is over gf/<sH2}
boolean bStop = false; //Stop identical fA),^
FileAccessI fileAccessI = null; //File Access interface /\E3p6\*
A "'h0D
1IK*j+%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException F9q!Upr_+
{ LftGA7uGJ)
this.sURL = sURL; Ve40H6Ox
this.nStartPos = nStart; ]2iEi`"[
this.nEndPos = nEnd; SxX
nThreadID = id; ;g<y{o"Q3p
fileAccessI = new FileAccessI(sName,nStartPos);//定位 OgCNqW d-
} bhfC2@
'\"5qB
81)i>]
public void run() @U =~c9
{ gaE8\JSr
while(nStartPos < nEndPos && !bStop) =}SLQdT
{ Hig.` P
g}*p(Tp9:
)k4&S{=
try{ ~!/agLwY
URL url = new URL(sURL); ?H8dyQ5"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]tmMk7
httpConnection.setRequestProperty("User-Agent","NetFox"); veS) j?4
String sProperty = "bytes="+nStartPos+"-"; 7<X!Xok
httpConnection.setRequestProperty("RANGE",sProperty); lKS 2OOYC`
Utility.log(sProperty); : TqeVf
X*&Thmee
FbW$H]C$
InputStream input = httpConnection.getInputStream(); ;i?R+T
//logResponseHead(httpConnection); iD>H{1 h
NpS =_QeNw
<J.q[fd1*
byte[] b = new byte[1024]; (Hs,Tj
int nRead; 'GLpSWL+*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) QEF$Jx
{ (!9+QXb'
nStartPos += fileAccessI.write(b,0,nRead); Ghar hJ>v
//if(nThreadID == 1) d8p5a C+E
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qGP}
} I(Vg
j%81q
&@D\4b,?nm
Utility.log("Thread " + nThreadID + " is over!"); z<9Llew^e
bDownOver = true; '7.4!I0'
//nPos = fileAccessI.write (b,0,nRead); ( F4c0
} gq}c
catch(Exception e){e.printStackTrace ();} IL"N_ux~w~
} H,LJ$ py
} U~oGg$
[Y^h)k{-$
9{IDw
//打印回应的头信息 q&LCMnv"P
public void logResponseHead(HttpURLConnection con) ylQ9Su>o
{ A}_pJH
for(int i=1;;i++) pxW*kS
{ R pT7Nr
String header=con.getHeaderFieldKey(i); ao@CPB6N
if(header!=null) XS.*CB_m_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vr_Z0]4`C9
Utility.log(header+" : "+con.getHeaderField(header)); ?R4%z2rcW
else 6<f(Zv? I
break; @\a~5CLN
} U+!&~C^y
} WDt6{5T
*0<)PJ T
F]s:`4
public void splitterStop() x_wWe>0
{ `dRqheX
bStop = true; F;BCSoO4
} ,}wFQ9*|W
^S!;snhn
xRqA^Ad
} MXDUKh7v3
Ms-)S7tMz
"ZFH_5<
/* pv"s!q&
**FileAccess.java |AS<I4+&
*//文件访问(定位，写) f{P?|8u
package NetFox; Wmx3@]<
import java.io.*; fm q(!
NB-%Tp*d
8fPTxvXqL
public class FileAccessI implements Serializable{ >oC{YYcK
`O0y8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 d;{k,rP6
RandomAccessFile oSavedFile; O9AFQ)u
long nPos; Ep3I*bQ Y
aS~~*UHW
[*@ +
public FileAccessI() throws IOException eDvh3Y<D
{ `oM'H+
this("",0); "+Sq}WR
} _z9~\N/@[
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XCO8A\
public FileAccessI(String sName,long nPos) throws IOException vb}c)w dp?
{ dEW= V"W
oSavedFile = new RandomAccessFile(sName,"rw"); mmy/YP)
this.nPos = nPos; v7%}ey[
oSavedFile.seek(nPos); J|<C;[du>
} Np/vPaAk
U=5~]0g
(*AJ6BQWa
public synchronized int write(byte[] b,int nStart,int nLen) "{zqXM}:C
{ G#A6<e/
int n = -1; 3{wuifS
try{ 6{yn;D4
oSavedFile.write(b,nStart,nLen); _'*(-K5&
n = nLen; r`<x@,
} 8q; aCtei
catch(IOException e) %P:|B:\<
{ [6Sk>j
e.printStackTrace (); vG\ b`
} @jrxbo;5
^)C#
ew]G@66
return n; 7nP{a"4_
} eBY/Y6R
KL$>j/qT
W>:MK-_J
} NQqNBI?cr
`,4@;j<^@
Bx6,U4o*
/* >Psq" Xj
**SiteInfoBean.java a2/Mf
*/ fzvyR2 I
package NetFox; OXn-!J90P
O,S>6o)?
-)R =p"-w
public class SiteInfoBean { [(&aVHUj
s)KlKh
$\bVu2&I
private String sSiteURL; //Site's URL VN'\c3;
private String sFilePath; //Saved File's Path S(CVkCP
private String sFileName; //Saved File's Name 'fCSP|
private int nSplitter; //Count of Splited Downloading File LXPO@2QF
2A9crL$
C%CgWO`Xj
public SiteInfoBean() q?@*
{//nSplitter的缺省值为5 v>N*f~n
//default value of nSplitter is 5 Wu(^k25
this("","","",5); _x^rHADp
} i ^2A:6}?
AlkHf]oB
N">#fYix
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) o$V0(1N
{ 'f.k'2T
sSiteURL= sURL; WWo"De@
sFilePath = sPath; e,lLHg
sFileName = sName; ]E'?#z.t
this.nSplitter = nSpiltter; !nlr!+(fV
xEeHQ7J
7AWq3i{
} PN:`SWP
OhlK;hvdB*
62y:i
public String getSSiteURL() "fUNrhCx
{ axq~56"7E
return sSiteURL; \fuz`fK:
} pZ3sp!
lP*=4Jh
#f/4%|t:
public void setSSiteURL(String value) [IAk9B.\
{ )=MK&72r
sSiteURL = value; 5SmJ'zFO
} dQ9W40g1
1eEML"
}pnp._j
public String getSFilePath() z( }w|
{ -;FAS3(wy
return sFilePath; ;Krb/qr4_
} w5 ]lU
%Lb cwh(9
d|9]E&;,
public void setSFilePath(String value) c2fSpvz
{ B& R?{y*
sFilePath = value; 67Qu<9}<-
} 78~/1-
m^3j|'mG
11kyrv
public String getSFileName() jb{9W7;RL
{ *'aouS/?<6
return sFileName; dU2;
} !`1m.
O:pg+o&
|v5 ge3-
public void setSFileName(String value) ~I%164B+/
{ nZ(wfNk
sFileName = value; TW70z]B
} >5"e<mwD7d
E)f9`][
gA}<Y
public int getNSplitter() 4VwMl)8ic
{ S]~5iO_bst
return nSplitter; b18f=<#
} j3T)gFP
VmN7a6a
P8|ANe1 v
public void setNSplitter(int nCount) yFQaNuZPC
{ 4 2DMmwB
nSplitter = nCount; u/-EVCHr y
} _nEVmz!zg
} ;134$7!Y
:FtV~^Z
F]r'j ZL
/* @TX@78fWz=
**Utility.java )*{B_[
*/ Sy4|JM-5
package NetFox; #s15AyKz5
3 H5
b4bd^nrqV
public class Utility { ?Tu=-ppw
N-knhA
" zD9R4\X.
public Utility() SK^(7Ws~0
{ R8eBIJ/@_
Dq$1 j%4Y
~gGkw#
} g,M-[o=Fk
d;wq@e
//线程睡眠 js"5{w&
public static void sleep(int nSecond) )oz2V9X{
{ &GJVFr~z
try{ F;h^o!W7r
Thread.sleep(nSecond); B)1(
} K[0z$T\
catch(Exception e) D15-pz|Q
{ u a_w5o7
e.printStackTrace (); g\@.qKF
} S.1>bs2
} Ol+D"k~<C
]?wz.
//日志 hfyU}`]
public static void log(String sMsg) $@71 w~y
{ QRBx}!:NZ#
System.err.println(sMsg); vt*
} ~ss6yQ$
g52)/HM
JJSE@$",\
public static void log(int sMsg) C58o="L3S
{ j>:N0:
System.err.println(sMsg); nGYimRYO
} TNA7(<"fV|
} qm:C1#<p
~D4l64
j4=iHnE;
/* `67i1w`
**TestMethod.java {z0iWY2Xw
*/ Ng*-Bw)p]
package NetFox; aGi`(|shW
|m"Gr)Gm
x4L3Z__
public class TestMethod { q{f\_2[
r~f;g9I
.udLMS/_
public TestMethod() >c<xy>N
{ ///xx/weblogic60b2_win.exe UdM2!f
try{ ./Ek+p*96H
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6o3#<ap<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); y2s(]#8
SiteFileFetch fileFetch = new SiteFileFetch(bean); j=M%*`@
fileFetch.start(); BSgT 6K
} ?2Z`xL9QT
catch(Exception e){e.printStackTrace ();} 6Q]c}
Z@&%"nO
tUc<ExvP,
} M."/"hV`-
([>__c/Nd
J9*;Bqzim
public static void main(String[] args) 7_l Wr
{ uyB2
new TestMethod(); TaHcvjhR
} LDHu10l
} \ f+;X
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