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)); w2lO[o~x}
} z('t#J!b
for(int i=0;i<nEndPos.length-1;i++) `/B+
{ -q?,
nEndPos = nStartPos[i+1]; ^^a%Lz)U
} IaO&f<^#o
nEndPos[nEndPos.length-1] = nFileLength; vCOtED*<
} k6RH]Ha
} Ya!PV&"Z
?_T[]I'
*|;`Gp
//启动子线程 QDKY7"H
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,<s:* k
for(int i=0;i<nStartPos.length;i++) 8{6`?qst@
{ @_ UI;*V
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "/3YV%to-#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6X4r2Vq
nStartPos,nEndPos,i); # 00?]6`z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U% ?+N
fileSplitterFetch.start(); 38:5g_
} u4 ~.[3E*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ies` !W^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .VohW=D3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", J?hs\nA
nEndPos = " + nFileLength); Zv8_<>e
// fileSplitterFetch[nPos.length-1].start(); J'k^(ZZ
wb##|XyK<c
v(, tu/
//等待子线程结束 l701$>>
//int count = 0; ]c6h'}
//是否结束while循环 ~b4kV)[ q
boolean breakWhile = false; K=pG,[ChA
b8Hzl!zO
53^3..E|
while(!bStop) JLg/fB3%
{ OAgZeK$
write_nPos(); Id8e%)
Utility.sleep(500); E;q+u[$
breakWhile = true; >T{TE"XyO|
C@pn4[jTl
OXB 5W#$
for(int i=0;i<nStartPos.length;i++) C3 BoH&
{ d vo|9>
if(!fileSplitterFetch.bDownOver) JcfGe4
{ ZzP&Zrm
breakWhile = false; oqg +<m
break; ^)aj,U[
} _'n]rQ'
} TJZarNc$
if(breakWhile) G6xNR
break; 8m[o*E.4F
KJs`[,;<
QcjsQTAbk
//count++; 7Rc>LI* '
//if(count>4) 6:Y2z!MLO
// siteStop(); vjA!+_I6
} @twi<U_
.*z$vl
\c!e_rZ
System.err.println("文件下载结束！"); V=YDqof
} gN*b~&G
catch(Exception e){e.printStackTrace ();} SA%)xGRW
} rMw$T=Oi
QB;TQZ
yf4 i!~
//获得文件长度 ~3%aEj
public long getFileSize() Y3-f68*(
{ xZ SDA8kS
int nFileLength = -1; gtqtFrleG
try{ S@TfZ3Go|
URL url = new URL(siteInfoBean.getSSiteURL()); <Ynrw4[)t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~n(LBA
httpConnection.setRequestProperty("User-Agent","NetFox"); `\/\C[Gg
$FZcvo3@*S
pOhjq#}
int responseCode=httpConnection.getResponseCode(); ^/xb-tuV
if(responseCode>=400) `B$Pk0>5r
{ C 7YS>?^]
processErrorCode(responseCode); |qU~({=b
return -2; //-2 represent access is error R0bgt2J
} FL&L$#X
Tr;&bX5]H
7g%\+%F I
String sHeader; '?LqVzZI
-<e_^
/"^XrVi-
for(int i=1;;i++) +k0UVZZX?
{ }%^3
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); JbN,K
//Utility.log(in.readLine()); \6pQ&an
sHeader=httpConnection.getHeaderFieldKey(i); Gh<#wa['}
if(sHeader!=null) 3T[zieX
{ czB),vooz
if(sHeader.equals("Content-Length")) zz8NBO
{ z(#dL>d$'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :8N{;aui
break; Qo*OC 9E`
} 1)f <
} >gl.ILo
else =Q6JXp
break; y I[kaH"J
} 42:,*4t(
} RVF<l?EI4R
catch(IOException e){e.printStackTrace ();} /2Ok;!.
catch(Exception e){e.printStackTrace ();} 6y"T;.FAo
[+!+Yn6:
M<Y{Cs
Utility.log(nFileLength); p<y\^a
p}Bh
g!z &lQnZ
return nFileLength; WHu[A/##']
} JIf.d($ ~:
[fs.D /
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//保存下载信息（文件指针位置） B3I0H6O
private void write_nPos() >LB*5
{ A+z}z@K
try{ 1DN
output = new DataOutputStream(new FileOutputStream(tmpFile)); =NWzsRl,
output.writeInt(nStartPos.length); G-#rWZ&
for(int i=0;i<nStartPos.length;i++) ):n'B` f}z
{ Dv4H^
// output.writeLong(nPos); -a'D~EGB^
output.writeLong(fileSplitterFetch.nStartPos); c(!pcB8
output.writeLong(fileSplitterFetch.nEndPos); 6QNZ/Ox:
} q2;CvoF
output.close(); .k%/JF91n
} 6LqF*$+$`
catch(IOException e){e.printStackTrace ();} Hr \vu`p$
catch(Exception e){e.printStackTrace ();} :!FGvR6
} w8#ji 1gX
i8#:y`ai
162Dj$
//读取保存的下载信息（文件指针位置） &G?w*w_n
private void read_nPos() 3PkU>+.6
{ 08g2? 5w"
try{ 6w_TL<S
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =%B}8$.|
int nCount = input.readInt(); *o<|^,R
nStartPos = new long[nCount]; Cn_r?1{W
nEndPos = new long[nCount]; M} +s_h9
for(int i=0;i<nStartPos.length;i++) <X?xr f
{ rmdg~
nStartPos = input.readLong(); 6p.y/LMO
nEndPos = input.readLong(); 5fLp?`T
} 29&F_
input.close(); Bp4#"y2
} ?/(*cA
catch(IOException e){e.printStackTrace ();} QoMa+QTuc
catch(Exception e){e.printStackTrace ();} 9Fg:
} ={jj'X9
5D mSgP:
biU ?>R
private void processErrorCode(int nErrorCode) M7YbRl
{ =>O{hT^F
System.err.println("Error Code : " + nErrorCode); *=Ma5J.
} & sXMB
:z\||f
o?aF
//停止文件下载 wBEBj7(y
public void siteStop() c4bvJy8
{ 7Oi<_b
bStop = true; gyU=v{].
for(int i=0;i<nStartPos.length;i++) +KOhDtLMG
fileSplitterFetch.splitterStop(); }}Gkipp
'"h}l`
.s|5AC[
} q77Iq0VR
} q3|SZoN
//负责部分文件的抓取 BG6Lky/omz
**FileSplitterFetch.java TZdJq
*/ \7e4t
package NetFox; KYq<n& s
0;%\L:,O
ly@%1
import java.io.*; x6vkd%fCj
import java.net.*; R?J8#JPXD
{@PZlQg
g9IIC5
public class FileSplitterFetch extends Thread { jPg[LZQ'
0QEcJ]Qb8
TjpAJW@-
String sURL; //File URL &7Xsn^opku
long nStartPos; //File Snippet Start Position ${97G#
long nEndPos; //File Snippet End Position $-(lp0\*
int nThreadID; //Thread's ID _6L'}X$)N
boolean bDownOver = false; //Downing is over YI]/gWeu
boolean bStop = false; //Stop identical %2beoH'
FileAccessI fileAccessI = null; //File Access interface |{rhks~
9MbF:
4%6@MQ[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |Vp ?
{ `*]r+J2
this.sURL = sURL; aaI5x
this.nStartPos = nStart; SXV2Y-
this.nEndPos = nEnd; <irr.O
nThreadID = id; EWWCh0 {
fileAccessI = new FileAccessI(sName,nStartPos);//定位 JZqJ&
} oMNBK/X_
{<cgeH
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public void run() DP!8c
{ J@rBrKC
while(nStartPos < nEndPos && !bStop) }t1 q5@QU
{ D<[kbt5^7
eGWwPSIp
"M,Hm!j
try{ =~q$k
URL url = new URL(sURL); `Y,Rk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I~-sBMm(w
httpConnection.setRequestProperty("User-Agent","NetFox"); 6~6 vwp
String sProperty = "bytes="+nStartPos+"-"; .{(gku>g(
httpConnection.setRequestProperty("RANGE",sProperty); :1~4X
Utility.log(sProperty); D8b9T.[(
-)DxF<8B
H8E#r*"-m
InputStream input = httpConnection.getInputStream(); _OK!/T*FBt
//logResponseHead(httpConnection); ?` 2z8uD/
7bR[.|T
hl,x|.f}4Y
byte[] b = new byte[1024]; `J;g~#/k
int nRead; lEw!H^O4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |w>d]eA5
{ ,5x9o"N!
nStartPos += fileAccessI.write(b,0,nRead); R,-DP/ (im
//if(nThreadID == 1) <4I`|D3@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E:P_CDSd]
} UUvR>5@n
k7 Ne(4P
xzf/W+.>.
Utility.log("Thread " + nThreadID + " is over!"); ~e5E%bXxC
bDownOver = true; mlz|KI~\F;
//nPos = fileAccessI.write (b,0,nRead); Z/OERO
} }3-`e3
catch(Exception e){e.printStackTrace ();} o%$R`;
} p`'3Il3
} )0=H)k0
G(1_P1
%htwq]rZd
//打印回应的头信息 /K<>OyR?
public void logResponseHead(HttpURLConnection con) iS`ok
{ 6s$h _$[X
for(int i=1;;i++) ?~oc4J*>(
{ :S+Bu*OyH
String header=con.getHeaderFieldKey(i); 0.B'Bvn=s2
if(header!=null) _V3}F1?W
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9CZEP0i7
Utility.log(header+" : "+con.getHeaderField(header)); i~m;Ah,#
else M2A_T.F=H
break; sDkO!P
} TR:4$92:H
} WKq{g+a
i,l$1g-i
Z{_YH7_
public void splitterStop() (?P\;yDG
{ Qn@[{%),4
bStop = true; Yr>7c1FZi
} WH.3
fhro"5/4
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} 161IWos
|
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/* M[0NB2`Wp
**FileAccess.java 9]|C$;kw@
*//文件访问(定位，写) y!~ }7=
package NetFox; (^~~&/U_U$
import java.io.*; +y 48.5
mS+sh'VH
f~f)6XU|
public class FileAccessI implements Serializable{ /WIH#M
{7EpljH@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 w%%*3[--X
RandomAccessFile oSavedFile; J #;|P-pt
long nPos; H9[0-Ur5
Hr*xAx
2xv[cpVi
public FileAccessI() throws IOException Q|7m9~
{ )p{,5"0u
this("",0); p }3$7CR/
} R^yh,
43!E>mq
)J 8mn*
public FileAccessI(String sName,long nPos) throws IOException [u^~ND'
{ c+ aTO"
oSavedFile = new RandomAccessFile(sName,"rw"); $IJ"fs
this.nPos = nPos; v `;Hd8
oSavedFile.seek(nPos); yxi*4R
} {^R>H|~
".kH5(:
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public synchronized int write(byte[] b,int nStart,int nLen) zuJ@@\75
{ m=60a@o]
int n = -1; g2YE^EKU~
try{ z#6(PZC}
oSavedFile.write(b,nStart,nLen); ,]tMZ?n8
n = nLen; m-Qy6"eW
} ?:+p#&I
catch(IOException e) Am >b7Z!
{ {gB9EGY
e.printStackTrace (); 9r 5(
} <jh=W9.N_
<9S5
;S'1fci6
return n; x}OJ~Yk]
} NOl/y@#
z -'e<v;w
/lc4oXG8
} oW6b3Q/B
|)[&V3+|
R?#.z#
/* UTO$L|K
**SiteInfoBean.java r<DPh5ReY
*/ `6v24?z
package NetFox; m:cWnG
EfX,0NqT
cEK#5
public class SiteInfoBean { P9M%B2DQ6f
*,,:;F^
hcR^?
private String sSiteURL; //Site's URL 5m?9O7Pg
private String sFilePath; //Saved File's Path Q5*"t*L!N
private String sFileName; //Saved File's Name -`1)yhS
private int nSplitter; //Count of Splited Downloading File -2Dgr\M
N({-&A.N
_RWH$L9
public SiteInfoBean() M`?ATmYy
{//nSplitter的缺省值为5 )!'7!" $
//default value of nSplitter is 5 yp<)v(8|'
this("","","",5); R+9 hog
} k>:\4uI|<\
&x/Z{ut
,E2c9V'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) soA] f
{ zG<>-?q~'
sSiteURL= sURL; b6@0?_n
sFilePath = sPath; %z-n2%
sFileName = sName; -#r=
this.nSplitter = nSpiltter; 'K|F{K
4Dasj8GsV
pJ/{X=y
} +ux`}L(
1/A|$t[
5qkyi]/U8
public String getSSiteURL() ',I$`h
{ vQ>8>V
return sSiteURL; Lv *USN
} $I9U.~*
nQG<OVRClS
yjM!M|
public void setSSiteURL(String value) 8L*#zaSAf
{ ~31-)*tJ]
sSiteURL = value; 4\ny]A:~
} ?_. SV g
Pxgal4{6
r|ogF8YN
public String getSFilePath() x)f<lZ^L&H
{ '~xiD?:
return sFilePath; Sy^@v%P'A
} kE1k@h#/
+[pJr-k
)2R]KU_=g
public void setSFilePath(String value) srH.$Y;~
{ Bd[H@oKru
sFilePath = value; ZpZoOdjslV
} 1czU$!MV
sAjN<P
W2A!BaH%
public String getSFileName() 5?TX.h9B4
{ )9+H[
return sFileName; E>F6!qYm
} peVzF'F
#/)U0IR)
r<'B\.#tp>
public void setSFileName(String value) %< Jj[F
{ %/R[cj8
sFileName = value; /.(F\2+A
} FmQiy+.|
QG09=GQ
T )bMHk
public int getNSplitter() ~jJe|zg>
{ _;:B@Z
return nSplitter; ^vTp.7o~5
} .xtam 8@
4!Lj\.!$
* K0aR!
public void setNSplitter(int nCount) f_IsY+@
{ -90X^]
nSplitter = nCount; %/RT}CBBsW
} c\rP"y|S};
} rC6EgWt<V
wLo<gA6;
IC-W[~
/* BuS[(
**Utility.java 3*eS<n[uG
*/ E-#C#B
package NetFox; b3q&CJ4|
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4"Mq]_D
public class Utility { LKst QP!I
B8zc#0!1
`bZgw
public Utility() ^C;ULUn3
{ i \@a&tw
\sS0@gnDI
H)5"<=]
} ?qbq\t
%5j*e
//线程睡眠 Bu4@FIK!C
public static void sleep(int nSecond) ^-(DokdBn
{ [vxHsY3z
try{ `Cz_^>]|=
Thread.sleep(nSecond); ^NO4T
} m5cRHo<9Y
catch(Exception e) LVJn2t^
{ =lx~tSiS
e.printStackTrace (); ra^"Vr
} >&Y\g?Z6G
} p-,Bq!aG$
-K6y#O@@
//日志 yER
public static void log(String sMsg) U"L-1]L
{ Bx|h)e9
System.err.println(sMsg); [NbW"Y7
} 0m4'm<2m
5`q#~fJ2
~F>'+9?Sn
public static void log(int sMsg) Xl E0oN~{
{ (SByN7[gb
System.err.println(sMsg); ?B<.d8i
} Myh?=:1~(c
} f\H1$q\p\
4j<[3~:0 o
1eI_F8I U
/* @su!9]o
**TestMethod.java l$m}aQ%h
*/ </W"e!?X
package NetFox; @%r"7%tq>
n_*.i1\'w
rGay~\
public class TestMethod { =sk#`,,:
=0SJf 3
j2mMm/kq\
public TestMethod() Qki? >j"
{ ///xx/weblogic60b2_win.exe I 1Yr{(ho
try{ Nr`v|_U
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); M0%nGpVj>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); X=Jt4 h9
SiteFileFetch fileFetch = new SiteFileFetch(bean); T[2<_nn=
fileFetch.start(); sk@aOv'*(
} Asj<u!L
catch(Exception e){e.printStackTrace ();} j? Vs"d|
_.SpU`>/f
[<nd+3E
} )-25?B
`tl-] ^Y2
fP llN8n
public static void main(String[] args) qf{HGn_9~1
{ mv(/M t
new TestMethod(); ^grDP*;W
} UkC'`NWF*
} *T:jR
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