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)); ^BW8zu@=O
} L6ypn)l
for(int i=0;i<nEndPos.length-1;i++) K5??WB63B
{ ?`6Mfpvj96
nEndPos = nStartPos[i+1]; Y/pK
} ,Z7Ky*<j
nEndPos[nEndPos.length-1] = nFileLength; mmCGIX
} b!nA.`T
} 3x z z* <
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4! F$nmG)
//启动子线程 XIl#0-E0X
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -Hy> z
for(int i=0;i<nStartPos.length;i++) .f!:@fX>=
{ k ,r*xt
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s5MG#M 9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %?8.UW\m
nStartPos,nEndPos,i); 6{fo.M?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Qkw_9
fileSplitterFetch.start(); &W&A88FfZU
} NL!xkcXO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s=z$;1C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [?g}<fa
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", AU9:Gu@M/
nEndPos = " + nFileLength); 2+R]q35-
// fileSplitterFetch[nPos.length-1].start(); pF}E`U=Z
0$U\H>r
q>6,g>I
//等待子线程结束 Lg2PP#r
//int count = 0; c^5fhmlt
//是否结束while循环 th0>u.hJ
boolean breakWhile = false; 6k+tO%{~
^nQJo"g\
G,(Xz"`,
while(!bStop) uD ;T
{ >Tn[CgH]7
write_nPos(); Dr}elR>~G=
Utility.sleep(500); K;TTGK
breakWhile = true; xq%BR[1
m&s;zQ
vJ&35nF&
for(int i=0;i<nStartPos.length;i++) i9peQ61{
{ eV0eMDY5
if(!fileSplitterFetch.bDownOver) V{}TG]
{ v)*eLX$
breakWhile = false; 7CX5pRNL
break; DnF|wS
} _~*ba+{
} CdtwR0
if(breakWhile) R F;u1vEQ8
break; \z.p [;'ir
S@4bpnhK
(YYwn@NGj
//count++; Y`xAJ#= ,i
//if(count>4) Xxm7s S
// siteStop(); /5\{(=0
} o+S?j*mv@
b}hQU~,E
V:gXP1P
System.err.println("文件下载结束！"); oV~S4|9:
} 8yuTT^
catch(Exception e){e.printStackTrace ();} owO&[D/
} pT;xoe
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mx2Ov u
//获得文件长度 dmMrZ1u2
public long getFileSize() QCfR2Nn}
{ 9a'}j#mJo
int nFileLength = -1; 3BB/u%N}
try{ g_"B:DR
URL url = new URL(siteInfoBean.getSSiteURL()); @ZcI]G%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8%b-.O:_$
httpConnection.setRequestProperty("User-Agent","NetFox"); xQqZi b5I
)/bv@Am
xp"F)6
int responseCode=httpConnection.getResponseCode(); &Hl w2^
if(responseCode>=400) ip*UujmNyR
{ tYUo;V
processErrorCode(responseCode); q6P5:@
return -2; //-2 represent access is error qp/nWGj
} X>MDX.Z
y*I,i*iv
)fc+B_
String sHeader; o~VZ%B
s 8lfW6
X@~R<
for(int i=1;;i++) _+&/P&
{ >i2WYT
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); D#X&gE
//Utility.log(in.readLine()); :Z3]Dk;y
sHeader=httpConnection.getHeaderFieldKey(i); {=P}c:iW
if(sHeader!=null) k_ijVfI9
{ B)&z% +
if(sHeader.equals("Content-Length")) 2K{)8;^
{ tSunO-\y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); er>@- F7w
break; Mbtk:GuY
} |<LW(,|A
} 5^36nEoA(
else &3YXDNm
break; .[vYT.LE
} @P<Mc)o^
} M`|E)Y
catch(IOException e){e.printStackTrace ();} q>VvXUyK,
catch(Exception e){e.printStackTrace ();} ,)t/1oQ}>^
?#u_x4==e
Yg]!`(db
Utility.log(nFileLength); ?L>}( {9
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o 0H.DeP
return nFileLength; g|x*sZR~Y
} X@@7Qk
3}i(i0+
ljk,R G
//保存下载信息（文件指针位置） +Pb@@C&
private void write_nPos() ~P+;_
{ S~.%G)R
try{ WL1$LLzN
output = new DataOutputStream(new FileOutputStream(tmpFile)); -KiI&Q
output.writeInt(nStartPos.length); Ny 7vId
for(int i=0;i<nStartPos.length;i++) 7^Y`'~Y^
{ s^-o_K\*c
// output.writeLong(nPos); e1 P(-V
output.writeLong(fileSplitterFetch.nStartPos); >W=^>8u
output.writeLong(fileSplitterFetch.nEndPos); biAa&
} wRQMuFGY
output.close(); 3aEO9v,n
} _S6SCSFc
catch(IOException e){e.printStackTrace ();} $WZHkV
catch(Exception e){e.printStackTrace ();} -|/*S]6kK
} )F%zT[Auph
4Pr@<S"U
v^1n.l %E
//读取保存的下载信息（文件指针位置） wXUgxa
private void read_nPos() lgh+\pj
{ RJA#cv~f
try{ pL{:8Ed
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k\lU Q\/O5
int nCount = input.readInt(); 8POLp9>X
nStartPos = new long[nCount]; '8UhYwyr
nEndPos = new long[nCount]; qJEtB;J'
for(int i=0;i<nStartPos.length;i++) #^bn~
{ Ia*T*qJu
nStartPos = input.readLong(); K7]IAV
nEndPos = input.readLong(); (Ei} :6,}
} jI,?*n<
input.close(); y_f^ dIK*=
} &W-1W99auE
catch(IOException e){e.printStackTrace ();} <=PYu:]h
catch(Exception e){e.printStackTrace ();} >&uR=Yd
} 1_G5uHO
6yXMre)YV
(,2U?p
private void processErrorCode(int nErrorCode) kDK0L3}nr]
{ Zi ;7.PqL
System.err.println("Error Code : " + nErrorCode); 5:X^Q.f;
} 1F94e)M)"
UpCkB}OhR1
"!_,N@\t
//停止文件下载 @!2vS@f
public void siteStop() (c1Kg
{ mA0|W#NB
bStop = true; ='\E+*[$I
for(int i=0;i<nStartPos.length;i++) 4W36VtQ@E
fileSplitterFetch.splitterStop(); '' Pfs<!
nO .:f
7?"-NrW~
} %2EHYBQjN
} .vhEm6wJUM
//负责部分文件的抓取 Kma-W{vGD
**FileSplitterFetch.java t gHXIr}3
*/ 2N}h<Yd9
package NetFox; H(F9&6}
,kw:g&A
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import java.io.*; O*+,KKPt
import java.net.*; yu@u0vlc
FpFkZFtG'm
+]jJ:V
public class FileSplitterFetch extends Thread { 95hdQ<W
WS1$cAD2N
H5?H{
String sURL; //File URL QKtVwsz +
long nStartPos; //File Snippet Start Position :ej`]yK |
long nEndPos; //File Snippet End Position pQ9~^
int nThreadID; //Thread's ID g%T`6dvT
boolean bDownOver = false; //Downing is over DYaOlT(rE
boolean bStop = false; //Stop identical 'w~e>$WI
FileAccessI fileAccessI = null; //File Access interface 'v'=t<wgl
MFO1v%m
WiCJhVF3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException gaxxB]8
{ `*HM5 1U
this.sURL = sURL; <-Q0s%mNj,
this.nStartPos = nStart; OIdoe0JR:O
this.nEndPos = nEnd; wQw y+S
nThreadID = id; _V_GdQ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $>!tpJw
} 1i:Q %E F
[-'LJG Wb<
i $;y
public void run() K1[(%<Gp
{ +n&9ZCH
while(nStartPos < nEndPos && !bStop) %6HJM| {H
{ `} :~,E
=X}s^KbI{
AG(Gtvw
try{ &VfMv'%x
URL url = new URL(sURL); pQ yH`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); njg\y
httpConnection.setRequestProperty("User-Agent","NetFox"); TwLQ;Q
String sProperty = "bytes="+nStartPos+"-"; T6N~L~J
httpConnection.setRequestProperty("RANGE",sProperty); d+158qQOh]
Utility.log(sProperty); l F*x\AT
M5<cHE
U((mOm6
InputStream input = httpConnection.getInputStream(); 8$C?j\J|*
//logResponseHead(httpConnection); l~*D jr~
^muPjM+D
&24$*Oe
byte[] b = new byte[1024]; $|pD}
int nRead; gzeTBlXg
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !<W^Fh
{ 2<33BBlWA
nStartPos += fileAccessI.write(b,0,nRead); hz*H,E!>
//if(nThreadID == 1) VAet!H+]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^F4h:
} )2mvW1M=7;
q_[V9
_8'z"wF
Utility.log("Thread " + nThreadID + " is over!"); ^b@&O-&s
bDownOver = true; wwVg'V;
//nPos = fileAccessI.write (b,0,nRead); j2%?-(U
} 6UnWtLE
catch(Exception e){e.printStackTrace ();} 6h3TU,$r
} L+J)
} ePxwN?
bo04y)Iz
.:V4>
//打印回应的头信息 do&0m[x%
public void logResponseHead(HttpURLConnection con) =%ZR0cWPoI
{ &&K"3"um
for(int i=1;;i++) _ !H8j/b
{ ".:]?Lvt
String header=con.getHeaderFieldKey(i); FvaelB
if(header!=null) T }^2IJ]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (Q~(t
Utility.log(header+" : "+con.getHeaderField(header)); w6FVSU]sY
else lJ/{.uK
break; Z|IFT1K
} Sxg&73;ZV
} fOkB|E]
"pW@[2Dkx/
_ pKWDMB$z
public void splitterStop() ruK,Z,3Q
{ m0_B[dw
bStop = true; !:|[?M.`
} [>wvVv
=V*4&OU
&RbT&
} HC\\w-`<
QLum=YB
rtY4B~_
/* tFKR~?Gc
**FileAccess.java ``* !b>)
*//文件访问(定位，写) hD!9[Gb
package NetFox; 9o|#R&0
import java.io.*; ;|H(_J=6k
8bP4
IQA<xqX
public class FileAccessI implements Serializable{ T_1p1Sg
#RWHk
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 kFsq23Ne
RandomAccessFile oSavedFile; Mh;rhQ
long nPos; P|{Et=R`1
q26%Z)'nf
.?CumaU
public FileAccessI() throws IOException z3>oUq{
{ <"rckPv_H
this("",0); 4bZ +nQgLu
} 2W]y9)<c
PS${B
wM#BQe3t#
public FileAccessI(String sName,long nPos) throws IOException ?B`Yq\L)
{ XOi[[G}
oSavedFile = new RandomAccessFile(sName,"rw"); "=r"c$xou
this.nPos = nPos; zA?]AL(+YW
oSavedFile.seek(nPos); sB>ZN3ptH^
} UZq1qn@+
:\+\/HTbh
dxIt.h
public synchronized int write(byte[] b,int nStart,int nLen) GY;q0oQ,
{ 'ffOFIz|=I
int n = -1; wBK%=7
try{ L4,Ke
oSavedFile.write(b,nStart,nLen); ;r}>1LhN
n = nLen; ~0~f
} d3|oKP6
catch(IOException e) F&I ;E i
{ K@PQLL#yJp
e.printStackTrace (); |vY0[#E8&
} umo@JWr
_^)<d$R<
;Pi-H,1b
return n; w 9mi2=
} P,[O32i#
g@jAIy]
'!6Py1i
} g, %xGQ4+
AqzPwO^
%4Thb\T
/* iS"(
**SiteInfoBean.java 3+EAMn
*/ {LLy4m
package NetFox; u{o!#_o64
dw v(8
@!:~gQ
public class SiteInfoBean { =+qtk(p
u0@i3Po
t TAqln|
private String sSiteURL; //Site's URL Q/,bEDc&
private String sFilePath; //Saved File's Path >7VOytc
private String sFileName; //Saved File's Name lo*)%fy
private int nSplitter; //Count of Splited Downloading File AIvIQ$6}
cv b:FK
L.uX
public SiteInfoBean() %\ i 7
{//nSplitter的缺省值为5 gqje]Zc<
//default value of nSplitter is 5 ;:a>#{N
this("","","",5); {1Z`'.FU
} 5xm^[o2#y
Bw31h3yB
6_m5%c~;+r
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) K{}U[@_tS
{ X4:\Shb97
sSiteURL= sURL; )5}=^aqd
sFilePath = sPath; G $TLWfm
sFileName = sName; mZ^z%+Ca|
this.nSplitter = nSpiltter; kgX"LQh;[G
QQso<.d&
gNdEPaaFI
} G`B e~NU
tSVN}~1\
FYI*44E
public String getSSiteURL() 37hs/=x
{ oh k.;
return sSiteURL; FC:Z9{2!
} ieN}Ajl2
2nW:|*:/p6
v+NdO$o
public void setSSiteURL(String value) (j^Qa~{mG4
{ >~-8RM
sSiteURL = value; B\U9F5
} YRXXutm
Ak`7f$z
'~HCYE:5
public String getSFilePath() )~{T
{ Q ke8BRBn
return sFilePath; ~C1lbn b
} &_-,Nxsf
<9JI@\>
}Ut*Y*
public void setSFilePath(String value) d NQ?8P-&
{ "HCJ!
sFilePath = value; <l/QS3M
} _g|zDi^
xV&c)l>}
DJxe3<
public String getSFileName() I}djDtJ
{ ~)\9f 1O{^
return sFileName; k8!|WqfP
} /5qeNjI+2
m0}Pq{g
WmO.&zp
public void setSFileName(String value) 0p"l}Fu@`
{ !c}?u_Z/
sFileName = value; 3uSj5+@q6
} 5K_KZL-
,$i2vGd
ch|4"&g
public int getNSplitter() bC_qoI<
{ b-Q*!Ut
return nSplitter; +#%#QL
} %49P<vo`?
F E`4%X
$AGW8"
public void setNSplitter(int nCount) ;WydXQ}Q^
{ EW$.,%b1
nSplitter = nCount; !*[Fw1-J
} lD`@{A
} j#}wg`P"A
=ttvC"4?
Mnj\t3:
/* iME)Jl&
**Utility.java 8>U{>]WG
*/ #%Z 0!
package NetFox; c[p>*FnP
,\YlDcl':0
D<V[:~-o
public class Utility { ]]sy+$@~
@1+gY4g
1 u[a713O
public Utility() OoW,mmthj>
{ (d9G`
A_h|f5
gu~JB
} p"%K(NL
HuVx^y` @
//线程睡眠 y7f,]<%e_
public static void sleep(int nSecond) 8i epG
{ @ Sq =q=S
try{ N>zpxU {
Thread.sleep(nSecond); Th\w#%'N
} pr;n~E 'kq
catch(Exception e) Ch] `@(l
{ bD2):U*Fzo
e.printStackTrace (); *Z9Rl>
} g2Hz[C(
} O V"5:){
3^jkd)xw
//日志 _Wb3,E a=
public static void log(String sMsg) "b~-`ni
{ +69[06F
System.err.println(sMsg); 1<9=J`(H
} D+nKQ4
U"qR6
}s@ i
public static void log(int sMsg) i?HN
{ EPd9'9S
System.err.println(sMsg); %%-?~rjI
} MvCB|N"qy
} ;bYpMcH
ydZS^BqG
GLBzlZ?
/* yQ [n7du
**TestMethod.java > w-fsL
*/ sahXPl%;U
package NetFox; p2=+cS"HC
j7XUFA
uo TTHj7cq
public class TestMethod { J4) ?hS
)yTBtYw3
*3!#W|#=]N
public TestMethod() 'kBq@>
{ ///xx/weblogic60b2_win.exe yq=rv$.s
try{ up;^,I
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); FJ+n- \
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); n:8<Ijrh
SiteFileFetch fileFetch = new SiteFileFetch(bean); )c<X.4
fileFetch.start(); eZ G#op
} Hob n{E
catch(Exception e){e.printStackTrace ();} rw }wQP_'
EyDH-}Y
Ivx]DXR|
} WJ&a9]&C
4(D1/8
lzbAx
public static void main(String[] args) c}G\F$
{ @Rw]boC
new TestMethod(); '89nyx&W
} $/FL)m8.3
} eia>Y$
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