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)); @zJiR{Je-U
} .7+"KP:
for(int i=0;i<nEndPos.length-1;i++) g77:92
{ /vPr^Wv
nEndPos = nStartPos[i+1]; xP7mP+D
} Q]]M;(
nEndPos[nEndPos.length-1] = nFileLength; RJ-J/NhWyI
} sT,*<^
} w3;T]R*
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//启动子线程 "$3~):o
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s~A:*2\
for(int i=0;i<nStartPos.length;i++) #+ {%>f
{ d>0 j!+s
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R8Dn GR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _`Dz%(c
nStartPos,nEndPos,i); Hn]6re
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D7Ds*X`!l
fileSplitterFetch.start(); KDr)'gl&
} E?jb?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Gb.}af#v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (\4YBaGd
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", uFG ;AY|
nEndPos = " + nFileLength); qxHsmGV
// fileSplitterFetch[nPos.length-1].start(); BPu>_$C
zX8{(
&D`$YUl@
//等待子线程结束 b{,vZhP-
//int count = 0; [bEm D
//是否结束while循环 .VkLF6
boolean breakWhile = false; ):V)Hrq?x
ah!fQLMH
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while(!bStop) %p};Di[V
{ 7mYBxE/
write_nPos(); (N{
Utility.sleep(500); Jh%k:TrBm
breakWhile = true; |RI77b:pX
aIE\B4w
&_Z8:5e
for(int i=0;i<nStartPos.length;i++) y9Q"3LLic`
{ u"zQh|
if(!fileSplitterFetch.bDownOver) WhL1OG
{ Q?Uk%t\hwc
breakWhile = false; 0.!Q4bhD
break; v?h8-yed
} |9 4xRC
} l5_%Q+E_
if(breakWhile) 7@i2Mz/eV
break; wqp(E+&
dUpOg{I.x
~{s7(^ P
//count++; qzu%Pp6If
//if(count>4) LWP&Si*j
// siteStop(); I\ y>I?X
} :aMp,DfM]P
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bq`0$c%hN
System.err.println("文件下载结束！"); D\V (r\i
} Q_n9}LanP
catch(Exception e){e.printStackTrace ();} ]ipltR7k
} {~:F1J~=
x^]1m%
K\>CXa
//获得文件长度 Z=P=oldH
public long getFileSize() #-u?+Nk/
{ & pS5_x
int nFileLength = -1; Fh$Xcz~i
try{ '5"`H>[
URL url = new URL(siteInfoBean.getSSiteURL()); IK^jzx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GPnSdGLC
httpConnection.setRequestProperty("User-Agent","NetFox"); ceqYyVy
p![CH
~2*8pb 4
int responseCode=httpConnection.getResponseCode(); H@xIAL
if(responseCode>=400) y|@=j~}Zq
{ SpUcrK;1
processErrorCode(responseCode); f<0nj?
return -2; //-2 represent access is error ,M&[c|
} y(RK|r
3#Hx^H
N;6WfdA-
String sHeader; ]gQ4qu5
=1"8ua
xdH*[
for(int i=1;;i++) K-nf@o+
{ v+|N7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); W@x UR-}51
//Utility.log(in.readLine()); ZrFC#wJb
sHeader=httpConnection.getHeaderFieldKey(i); w(9.{zF|vQ
if(sHeader!=null) 8vcV-+x
{ Dyj5a($9"{
if(sHeader.equals("Content-Length")) -)tu$W*
{ \Podyh/;?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); dSb|hA}@
break; [S/]Vk|4
} l*]*.?m/5
} B&`hvR
else RYaf{i`
break; !#nlWX:~
} (Ia}]q
} <;.Zms${@
catch(IOException e){e.printStackTrace ();} +t R6[%
catch(Exception e){e.printStackTrace ();} z2&SZ.mk
h&Ehp
d"|XN{
Utility.log(nFileLength); <m80e),~
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return nFileLength; M? oK@i
} .Mw'P\GtM
Mrp'wF D
elZ?>5P$}
//保存下载信息（文件指针位置） XGEAcN
private void write_nPos() PY.c$)az>
{ 8| zR8L
try{ B3'qmi<
output = new DataOutputStream(new FileOutputStream(tmpFile)); d(w $! $"h
output.writeInt(nStartPos.length); \CL |=8[2
for(int i=0;i<nStartPos.length;i++) N G1]!Vz5
{ |8h<Ls_
// output.writeLong(nPos); F9ry?g=h
output.writeLong(fileSplitterFetch.nStartPos); ~<3qsA..
output.writeLong(fileSplitterFetch.nEndPos); :*e0Z2=
} #"6(Q2| l
output.close(); phUno2fH
} r+0"1\f3
catch(IOException e){e.printStackTrace ();} ]6</{b
catch(Exception e){e.printStackTrace ();} I~MBR2$9
} %lV&QQa
YcGSZ0vQ
Ywt_h;:
//读取保存的下载信息（文件指针位置） Y*O7lZuF%
private void read_nPos() AL}c-#GG
{ z?h\7 R
try{ y%=\E
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1^R@X
int nCount = input.readInt(); oDx*}[/
nStartPos = new long[nCount]; $# @G!
nEndPos = new long[nCount]; Q$W0>bUP
for(int i=0;i<nStartPos.length;i++) R,/?p
{ )dG7$,g
nStartPos = input.readLong(); \^?BC;s^C
nEndPos = input.readLong(); ];^A8?
} ^M PU?k
input.close(); Qwk
} O:RPH{D
catch(IOException e){e.printStackTrace ();} d37l/I
catch(Exception e){e.printStackTrace ();} E*7B5
} ?y'KX]/
,$mnD@)
t'_Hp},
private void processErrorCode(int nErrorCode) b'O>&V`
{ [sTr#9Z
System.err.println("Error Code : " + nErrorCode); e1S |&W8
} S,lJ&Rsu
Jj|HeZ1C f
,`G8U/
//停止文件下载 HW"|Hm$Y(
public void siteStop() 22`W*e@6h
{ NM/?jF@j*
bStop = true; kW4/0PD
for(int i=0;i<nStartPos.length;i++) gf2l19aP
fileSplitterFetch.splitterStop(); &iR>:=ksN
ly}6zOC\
A0cC)bd&
} fr;>`u[;
} J8J~$DU\Gv
//负责部分文件的抓取 ?zQ\u{]=
**FileSplitterFetch.java syA*!Up
*/ 9loWh5_1Z
package NetFox; 4gb2$"!
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7qA0bUee5
import java.io.*; U voX\
import java.net.*; dZIAotHN:
x:88E78
Y]P';C_eP
public class FileSplitterFetch extends Thread { ?5Wjy
#gMMhB=
>t)vQ&:;u
String sURL; //File URL ,icgne1j
long nStartPos; //File Snippet Start Position sczN0*w&C
long nEndPos; //File Snippet End Position _~&6Kb^*
int nThreadID; //Thread's ID A)kx,,[
boolean bDownOver = false; //Downing is over LUl6^JU
boolean bStop = false; //Stop identical =zDU!< U
FileAccessI fileAccessI = null; //File Access interface Yewn
}Xr-xh\v
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bvuoGG*
{ 6b~Zv$5^Y-
this.sURL = sURL; TUIj-HSe
this.nStartPos = nStart; |Up+Kc:z/n
this.nEndPos = nEnd; 0Jm6 r4s?
nThreadID = id; 8V>j-C
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8;ke,x
} WW{5[;LYiB
\{t#V ~
yQ}$G ,x
public void run() k<Z^93 S
{ T1m"1Q
while(nStartPos < nEndPos && !bStop) klxVsx%I{G
{ SG_^Rd9 D
<gF=$u|}3[
=@AWw:!:,
try{ !Y>lAxd
URL url = new URL(sURL); Yz=(zj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 15+>W4v
httpConnection.setRequestProperty("User-Agent","NetFox"); gELku .
String sProperty = "bytes="+nStartPos+"-"; n1m[7s.[&
httpConnection.setRequestProperty("RANGE",sProperty); OSQZ5:g|
Utility.log(sProperty); 1 0lvhzU
Ehi)n)HhG"
=.(yOUI
InputStream input = httpConnection.getInputStream(); ye:pGa w
//logResponseHead(httpConnection); `E+)e?z
&lbxmUeU
px %xoY
byte[] b = new byte[1024]; Xf!@uS6<X
int nRead; NUbw]Y90~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u~[HC)4(0
{ fuSfBtLPR#
nStartPos += fileAccessI.write(b,0,nRead); ^e:C{]S=
//if(nThreadID == 1) +%Q:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,A`d!{]5
} $}V<Um
1rKKph
&E0L7?l
Utility.log("Thread " + nThreadID + " is over!"); 6E/>]3~!
bDownOver = true; Zu`; S#Y
//nPos = fileAccessI.write (b,0,nRead); k4fc5P
} .) uUpY%K^
catch(Exception e){e.printStackTrace ();} B4yU}v
} *GleeJWz
} 74Xk^8
wI><kdz
UhN16|x
//打印回应的头信息 ,@kD9n5#
public void logResponseHead(HttpURLConnection con) 1^XuH('
{ 'N^\9X0
for(int i=1;;i++) vw5f.8T;w
{ Z:DEET!c'k
String header=con.getHeaderFieldKey(i); RO[Ko-m|/N
if(header!=null) ^]l^q'?>:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PPk\W7G
Utility.log(header+" : "+con.getHeaderField(header)); <~;;iM6
else '{dduHo
break; %E#OUo[y/
} #<0Yx9Jh.
} 59mNb:<
K~ ,|~
ZycV?ob8}
public void splitterStop() s3qWTdM
{ nfpkWyIu{
bStop = true; `q|&;wP.
} mAMi-9
**_`AM~
D,q=?~
} g?`g+:nug
.w2QiJ
Go~bQ2*'(/
/* BC*vG=a
**FileAccess.java _nu,ks+
*//文件访问(定位，写) Tlrr02>B{
package NetFox; IN=pki|.
import java.io.*; u$ [R>l9
+13h*
Fx,08
public class FileAccessI implements Serializable{ ^?PU:eS
>2h|$6iWP
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X8~dFjhX
RandomAccessFile oSavedFile; *uHL'Pe;m
long nPos; uo0g51%9
,:g.B\'Q
$$ %4,\{l
public FileAccessI() throws IOException y_O[r1MF
{ j !^Tw.Ty
this("",0); {Hncm
} :VwU2
2WQKj9iyN
].F7. zi
public FileAccessI(String sName,long nPos) throws IOException @_"B0$,-i
{ 1=BDqSZ@9
oSavedFile = new RandomAccessFile(sName,"rw"); Td#D\d\R
this.nPos = nPos; @P=St\;VP
oSavedFile.seek(nPos); OS8 ^mC
} I)#=#eI*:
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&:}e`u@5|
public synchronized int write(byte[] b,int nStart,int nLen) kk]f*[Zi5
{ gXr"],OM;
int n = -1; @3`:aWda
try{ Y `4AML
oSavedFile.write(b,nStart,nLen); 1'ne[@i^/
n = nLen; AA][}lU:5
} z_qy>
catch(IOException e) ~\= VSwJ
{ [A$5~/Q{U1
e.printStackTrace (); &v!=\Fig4
} pR_cI]{=SA
[ZwZGAP
yMdEH-?/
return n; `$og]Dn;
} zNSix!F
iVq4&X_x
").MU[q%Y
} *M5: \+
NGYliP,.6
>!+.M9
/* xlPUum-o
**SiteInfoBean.java TDI8L\rr
*/ wMy$T<:
package NetFox; m"Y;GzqQl
xml@]N*D#E
4d&#NP
public class SiteInfoBean { Ol,;BZHc\
36>pa
z0J$9hEg89
private String sSiteURL; //Site's URL ^NJ]~h{n$
private String sFilePath; //Saved File's Path Zgp]s+%E
private String sFileName; //Saved File's Name Y" 9 o
private int nSplitter; //Count of Splited Downloading File rkhQoYZ[
dz/' m7
@|Z:7n6S
public SiteInfoBean() :xw2\:5~0
{//nSplitter的缺省值为5 Ov3W;jD
//default value of nSplitter is 5 34VyR a
this("","","",5); -q7A\8C
} K/RQ-xd4
[?)=3Pp
216+ tX5Z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) VM{`CJ2
{ j]7|5mC78
sSiteURL= sURL; [vki^M5i|Z
sFilePath = sPath; u#5/s8
sFileName = sName; :LRR\v0HM
this.nSplitter = nSpiltter; \RN,i]c-g/
-_=0PW5{
MLg<YL
} pT]M]/y/:
&pwSd
#!p=P<4M
public String getSSiteURL() 6cof Zc$
{ >}QRMn|@H
return sSiteURL; {#q']YDe`
} y e!Bfz>
EM/NT/
f@l6]z{.L
public void setSSiteURL(String value) ~ZU;0#
{ C("PCD
sSiteURL = value; A7U'>r_.
} CG'NC\x5
R`=3lY;
3nuf3)
public String getSFilePath() Lm+!/e
{ ) Kfk\
return sFilePath; <B6@q4Q
} `NA[zH,w3
D^Dm, -
<'A>7M~h?*
public void setSFilePath(String value) C%d 4ItB >
{ 7}bjJR "
sFilePath = value; ];Whvdnv
} JV'd!5P
/=Ug}%.
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public String getSFileName() 2=ZR}8}9Q:
{ Z+ubc"MVb
return sFileName; Cus=UzL
} m%V+px
ZCPK{Ru QE
bHlG(1uf
public void setSFileName(String value) qG"|,bA
{ }]vj"!?a
sFileName = value; }@yvw*c
} +C7 1".i-
7=XQgbY/
l|`FW
public int getNSplitter() XuJwZN!(
{ 5_Yv>tx
return nSplitter; lEi,duS)
} oTtmn, T
vl$! To9R"
Wm:3_C +j
public void setNSplitter(int nCount) Pb?H cg
{ mm$D1=h{|
nSplitter = nCount; YVVX7hB
} 7ka^y k@Q
} OXDlwbwL
))c;DJc
lp[3z&u
/* c?) pn9
**Utility.java 6A M,1
*/ , >Y.!
package NetFox; _yjM_ALjo
T\c;Ra
?>MD/l(l
public class Utility { DHpU?;|3
t )Z2"_5
]SrKe-*:U
public Utility() [e)81yZG>
{ 80$P35Q"
yP0P-8
iM2 EEC
} fEs957$
`'Ta=kd3
//线程睡眠 ;t%L(J
public static void sleep(int nSecond) |PH]0.m5
{ !~UI~-i'
try{ OfTcF_%
Thread.sleep(nSecond); xmKa8']x
} j-gLX
catch(Exception e) ;TSnIC)c
{ CkoPno
e.printStackTrace (); 6uDA{[OH
} 9?D7"P+
} s cR-|GuZ
X1<)B]y
//日志 Y'fI4
public static void log(String sMsg) 'G(N,vu[@
{ $ajw]2kx
System.err.println(sMsg); y NV$IN%
} ?Z4&j'z<
};9dd3X
%W"\
public static void log(int sMsg) :Tuy]]k
{ gZM{]GQ
System.err.println(sMsg); L:Wy- Z
} 4NR,"l)
} miS+MK"
{J})f>x<xM
%>I!mD"X\
/* } Q1$v~
**TestMethod.java p<*-B
*/ 1)_f9GR
package NetFox; TG?;o/
?P`wLS^;
5[l3]HOO
public class TestMethod { >[|:cz
#*S/Sh?Q
1bzPBi
public TestMethod() ;ok];4`a
{ ///xx/weblogic60b2_win.exe 5B'-&.Aj+
try{ %c^]Rdl
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6FEtq,;0w
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /oiAAB27
SiteFileFetch fileFetch = new SiteFileFetch(bean); JS(KCY9
fileFetch.start(); hN\E8"To
} wT*N{).
catch(Exception e){e.printStackTrace ();} .6O>P2m]a_
Va=0R
AN:,t(w
} f~Kln^
!FHNKh
zN5i}U=|r
public static void main(String[] args) e}[$ =
{ 4] ?
new TestMethod(); oPa2GW8
} *qOo,e
} hNx`=D9[7
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