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)); >dW~o_u'QN
} i$A0_ZJKjZ
for(int i=0;i<nEndPos.length-1;i++) )`ZTu -|
{ \*V`w@
nEndPos = nStartPos[i+1]; C?3?<FDL
} XY;cz
nEndPos[nEndPos.length-1] = nFileLength; ?4U|6|1
} '}D$"2I*
} ^=nJ,-(h_
rU/V~;#%
kR0d]"dr
//启动子线程 ]~SOGAFW
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; xCOC5f5*@
for(int i=0;i<nStartPos.length;i++) CR-6}T
{ QJaF6>m
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V+mTo^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), JZ5NQ)sX
nStartPos,nEndPos,i); "@JSF
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X~O2!F
fileSplitterFetch.start(); xsq+RBJi
} F~cvob{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gt9{u"o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); luyU!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6Y|jK<n?H
nEndPos = " + nFileLength); ",\,lqV
// fileSplitterFetch[nPos.length-1].start(); 4$+9Wv
FBYAd@="2
75t\= 6#
//等待子线程结束 M8 E8r
//int count = 0; ?2b*FQe
//是否结束while循环 ;Q;u^T`
boolean breakWhile = false; Q-X<zn
S1<mO-
IQFt4{aK3
while(!bStop) j7vp@l6`L
{ L+}q !'8S
write_nPos(); ptS1d$
Utility.sleep(500); .cTK\
breakWhile = true; 6O^'J~wiI
\@6nRs8b|N
(Z YGfX
for(int i=0;i<nStartPos.length;i++) H}OOkzwrA
{ 5Mfs)a4j.
if(!fileSplitterFetch.bDownOver) cC_L4
{ D2`tWRm0
breakWhile = false; ic}M)S FD;
break; K0#kW \4`
} NM0[yh
} 8#gS{
if(breakWhile) lD;="b
break; !H`Q^Xf}
BTXS+mvl
[/}y!;3iXM
//count++; %E95R8SL
//if(count>4) #OKzJ"g
// siteStop(); I<q=lK
} *RQkL'tRf
"JLKO${ Y
7a@%^G @!
System.err.println("文件下载结束！"); R6ynL([xh
} }U=|{@%
catch(Exception e){e.printStackTrace ();} q$$:<*Uy
} e>-a\g
fX,L;Se"
X]J]7\4tF\
//获得文件长度 7gR8Wr ^
public long getFileSize() =(f+geA"hm
{ 'E2\e!U/
int nFileLength = -1; e Ir|%
try{ !%' 1x2?
URL url = new URL(siteInfoBean.getSSiteURL()); }s_'q~R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1nv#Ehorg
httpConnection.setRequestProperty("User-Agent","NetFox"); S4j`=<T,
j +j2_\
*t{$GBP
int responseCode=httpConnection.getResponseCode(); !c`KzqP
if(responseCode>=400) x/NR_~Rnk
{ qRg^Bp'VD#
processErrorCode(responseCode); <_HK@E<_HO
return -2; //-2 represent access is error gO*:<B g
} pu(a&0
03ol!|X"9
as1ZLfN.
String sHeader; yub|
D|W^PR:@h
oT7=
for(int i=1;;i++) SbNs#
{ >:whNp
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "HRoS#|\
//Utility.log(in.readLine()); uqy b
sHeader=httpConnection.getHeaderFieldKey(i); M{U{iS
if(sHeader!=null) Ih*}1D)7
{ ;$|[z<1RdW
if(sHeader.equals("Content-Length")) 3PB#m.N<
{ P@ewr}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); -c-#1_X5
break; C WJGr:}&
} {Mc^[}9
} bkQEfx.
else Vy;f4;I{
break; <MgR x9
} 2%YtMkC5
} >uS?Nz5/
catch(IOException e){e.printStackTrace ();} B+G,v:)R6z
catch(Exception e){e.printStackTrace ();} {EKzPr/
cd36f26`"w
0h~Iua5
Utility.log(nFileLength); $sDvE~f0n
N;cEf7+f
I g/SaEF
return nFileLength; ]Mu + DZ
} 8r^~`rL
pyEi@L1p
KX e/i~AS
//保存下载信息（文件指针位置） -aCtk$3
private void write_nPos() d'~sy>
{ 8}m bfuo1
try{ <szD"p|K
output = new DataOutputStream(new FileOutputStream(tmpFile)); nJJ9>#<g$
output.writeInt(nStartPos.length); Nf0'>`/
for(int i=0;i<nStartPos.length;i++) %vjLw`
{ Mg H,"G
// output.writeLong(nPos); \%nFCK0
output.writeLong(fileSplitterFetch.nStartPos); `8Y& KVhu
output.writeLong(fileSplitterFetch.nEndPos); +*2wGAT
} o9)pOwk7;
output.close(); Y>KRI2](<
} -!uut7Z|
catch(IOException e){e.printStackTrace ();} YNc]x>
catch(Exception e){e.printStackTrace ();} }`g:)gJ
} >}#h
&61;v@
7Y$#* 7
//读取保存的下载信息（文件指针位置） W2L:
private void read_nPos() D9H(kk
{ {R[FwB^7wJ
try{ F|K=].
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); rn^7B-V
int nCount = input.readInt(); O>)<w Ms`
nStartPos = new long[nCount]; 2s,[DC
nEndPos = new long[nCount]; a []Iz8*6e
for(int i=0;i<nStartPos.length;i++) v)|[=
{ & 2MI(9v
nStartPos = input.readLong(); csg:#-gE
nEndPos = input.readLong(); K31G>k@
} FLI\SF<
input.close(); L,*KgLG
} z;:c_y!f
catch(IOException e){e.printStackTrace ();} }q1@[ aE
catch(Exception e){e.printStackTrace ();} >C"f'!oM,j
} p F\~T>
)ndcBwQc"
a!MhxM5
private void processErrorCode(int nErrorCode) L8K=Q
{ 5y7rY!]Bf
System.err.println("Error Code : " + nErrorCode); #3@ Du(_n
} 2j_YHv$I
]3tg|?%B
;SAurG$
//停止文件下载 uU v yZ
public void siteStop() &fJ92v?%^S
{ ~F8M_
bStop = true; `IQ01FuP
for(int i=0;i<nStartPos.length;i++) -"qw5Y_oF?
fileSplitterFetch.splitterStop(); 7;dTQ.%n
Fj\}&H*+
%,$Ms?,n`
} t3ua5xw
} uP<w rlW
//负责部分文件的抓取 $mvcqn;
**FileSplitterFetch.java ]]lgCac_U9
*/ (4_7ICFI
package NetFox; )3<|<jwcx
EL!V\J`S_
4`lt 4L
import java.io.*; V{17iRflf
import java.net.*; 8<(qN>R
!@mV$nTA
^UP!y!&N
public class FileSplitterFetch extends Thread { )(~s-x^\z@
oJC-?
OgJd^
String sURL; //File URL s(56aE
long nStartPos; //File Snippet Start Position tydD~a
long nEndPos; //File Snippet End Position GOJ*>GpS
int nThreadID; //Thread's ID cU8Rm\?
boolean bDownOver = false; //Downing is over }X{#=*$GQ
boolean bStop = false; //Stop identical HRkO.230
FileAccessI fileAccessI = null; //File Access interface ^)ouL25Z*2
E"!I[
yM$@*od
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &7* |rshZ
{ USz|Rh
this.sURL = sURL; ;h[p "
this.nStartPos = nStart; oh+Q}Fa:
this.nEndPos = nEnd; 32!jF}qpD
nThreadID = id; V@gweci
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F"2v5F@
} nR)/k,3W
1e`/N+6u
x`8rR;N!
public void run() >|%dN jf@Q
{ RUcpdeo
while(nStartPos < nEndPos && !bStop) 5/j7C>
{ hwF9LD~^
_2Sb?]Xn
3xS+Pu\)
try{ utIR\e#:B
URL url = new URL(sURL); :V1ttRW}52
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eliT<sw8
httpConnection.setRequestProperty("User-Agent","NetFox"); A/n-.ci
String sProperty = "bytes="+nStartPos+"-"; i^j1i
httpConnection.setRequestProperty("RANGE",sProperty); 0$)CWah
Utility.log(sProperty); 2e_ssBbb
WP)r5;Hv`
DBDHe-1[+
InputStream input = httpConnection.getInputStream(); &YQ
//logResponseHead(httpConnection); 40TS=evG
KL:x!GsV5e
:^7P. lhK
byte[] b = new byte[1024]; e?W-vi%
int nRead; '<N^u@tF7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4W7
{ i#/,Q1yEn
nStartPos += fileAccessI.write(b,0,nRead); 2NS(;tBB0
//if(nThreadID == 1) 'n`+R~Kkh
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ; MU8@?yN
} C[f'1O7
Xup rl2+
w,hl<=:(FB
Utility.log("Thread " + nThreadID + " is over!"); ^mWOQ*zi;
bDownOver = true; ]IbX<
//nPos = fileAccessI.write (b,0,nRead); {"Xn`@Y
} b~;gj^
catch(Exception e){e.printStackTrace ();} [RtTi<F^
} h2kba6rwk
} ovv<7`
.FUws
VO#x+u]/
//打印回应的头信息 D$C>ZF
public void logResponseHead(HttpURLConnection con) D^cv 8 8<
{ N$1ZA)M
for(int i=1;;i++) lJaR,,
{ j`JY3RDD
String header=con.getHeaderFieldKey(i); W;~ f865
if(header!=null) (S1c6~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); on?<3eED
Utility.log(header+" : "+con.getHeaderField(header)); 2'O2n]{
else E`#m0Q(8
break; RLBeti>
} x*}41;j}C
} wf47Ulx
A*d Pw.
}j=UO*|
public void splitterStop() &)UZ9r`z
{ oNW.-gNT
bStop = true; y %R-Oc
} O@*7O~eO
V_b"^911r
5`su^
} ,;3#}OGg
}yQ&[Mt
P2y`d9,Q
/* l=EnK"aU
**FileAccess.java =T_E]>FF9
*//文件访问(定位，写) UQq,Xq
package NetFox; YU=Q`y[k
import java.io.*; >R9Q|
0,~f"Dyqy
iuxI$
public class FileAccessI implements Serializable{ *nb `DR
<2b&AF{En
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 r6 k/QZT
RandomAccessFile oSavedFile; m]C|8b7Y
long nPos; OIi8x? .~]
bv %Bo4s
yVF1*#"
public FileAccessI() throws IOException ~Mk{2;x
{ B4tC3r
this("",0); F"p7&e\W|l
} JQ5E;8J>
&BF97%E2
yT[CC>]l
public FileAccessI(String sName,long nPos) throws IOException 9W^sq<tR
{ b02V#m;Z
oSavedFile = new RandomAccessFile(sName,"rw"); D~~"wos
this.nPos = nPos; I,[njlO:
oSavedFile.seek(nPos); Jo%`N#jG
} g.L~Z1-
^\<nOzU?
\X3Q,\H @
public synchronized int write(byte[] b,int nStart,int nLen) JONfNb+
{ X#;n Gq)5
int n = -1; 4XL$I*;4
try{ zL8Z8eh">
oSavedFile.write(b,nStart,nLen); "LwLTPC2
n = nLen; i}&&rr
} P{T\zT
catch(IOException e) }kJfTsFS
{ n~c<[
e.printStackTrace (); E[Xqyp!<
} 0.pZlv
SB1j$6]OR7
DIsK+1
return n; -DVoO2|Dv
} u{| Q[hf[
EC9bCd-z
#@pgB:~lB
} b#uNdq3
=*0KH##%$
"0*yD[2
/* _#\e5bE=Z
**SiteInfoBean.java H1bHQB
*/ ni2GZ<1j
package NetFox; (-}:'5|Yj
GtuA94=!V&
_sp,,gz
public class SiteInfoBean { x3>ZO.Q
IOfxx>=3
W8blHw"
private String sSiteURL; //Site's URL lF[m*}l
private String sFilePath; //Saved File's Path LiG!xs
private String sFileName; //Saved File's Name Sb4^* $uz
private int nSplitter; //Count of Splited Downloading File /EIQMZuYp
0Cg}yyOz
`p!&>,lrk
public SiteInfoBean() "*U0xnI
{//nSplitter的缺省值为5 g2LY~
//default value of nSplitter is 5 qw?Wi%t(x8
this("","","",5); M2kvj'WWq
} @:dn\{Zsea
PFKl6_(
^ABtg#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |D% O`[k+
{ @=7[KMb
sSiteURL= sURL; "L0Q"t:
sFilePath = sPath; *5QN:
sFileName = sName; /3`yaYkSh
this.nSplitter = nSpiltter; +TZVx(Z&A
aZ,j1j0p
~hZr1hT6L
} 1^ijKn@6
&lCOhP#
/Hs\`Kg"!
public String getSSiteURL() !V'~<&
{ I!?)}d
return sSiteURL; tP:ER
} <(!~s><.
&ggOm
s/l>P~3=
public void setSSiteURL(String value) <.Dg3RH
{ q)l1tC72
sSiteURL = value; c W1`[b
} %{|67h
b$eN]L
@CtnV|
public String getSFilePath() ]@I>OcH
{ Z,~PW#8<&
return sFilePath; Ez/>3:;
} d4m@u$^1B
#AR$'TE#
DO 0
public void setSFilePath(String value) R0#'t+7^
{ \>\_OfY1W
sFilePath = value; Pil_zQ4
} !DM GAt\
${5E
aKFY&zN?
public String getSFileName() uhm3}mWv
{ h:AB`E1
return sFileName; (Fj"<
} ~c=F$M^"c
<^w4+5sT/
;d.gVR_V
public void setSFileName(String value) V2SHF
{ Q-?6o
sFileName = value; `qV*R 2
} FN<Sagj
l`Ae&nc6
8Sk$o.Gy
public int getNSplitter() 0m,q3
{ `< 82"cAT{
return nSplitter; hK UK#xx
} ?sW}<8\
[VE>{4]W
T<%%f.x[s
public void setNSplitter(int nCount) )&$mFwf
{ rhDiIO_
nSplitter = nCount; [;Jq=G8&t
} z?t75#u9.
} goOw.~dZ'
zGwM# -
oh7tE$"c
/* iOtf7.@
**Utility.java wzF%R{;
*/ P&h]uNu
package NetFox; Q0%s|8Jc
HPXJRQBE
I uC7Hx`z
public class Utility { cR=o!2O
tZY6{,K%4
;YZ'd"0v
public Utility() C^fn[plL
{ d[YG&.}+8j
P @~)9W
]2c0?f*Y7
} AqT}^fS
Khh}flRy
//线程睡眠 KJv[z
public static void sleep(int nSecond) F+]cFx,/
{ Ri>ZupQ6
try{ Dqc2;>
Thread.sleep(nSecond); UZ1Au;(|
} -' =?Hs.
catch(Exception e) >uxAti\
{ 3i#'osq
e.printStackTrace (); 2;x+#D8
} tHEZuoi
} (W.G&VSn)
4N5\sdi
//日志 /@1pm/>ZaN
public static void log(String sMsg) Fd#Zu.Np
{ AYAbq}'Yt
System.err.println(sMsg); "H]R\xp
} mRy0zN>?
,hWuAu6.L
{mB!mbr
public static void log(int sMsg) }S;A%gYm
{ w3&L 6|,
System.err.println(sMsg); K,,'{j2#f
} qFI19`?8E
} &YBZuq2?
kz G W/
`i!fg\qnK
/* VONC<wC
**TestMethod.java V@nZ_.
*/ L9]d$ r"
package NetFox; Fw8b^ew
DUwms"I,%
(o^?i2)g
public class TestMethod { !gcea?I
@SI,V8i
rl x6a@MiD
public TestMethod() QZ+G2$
{ ///xx/weblogic60b2_win.exe /I:&P Pff
try{ YRCOh:W*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); RN$>!b/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6m@B.+1
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ed+jSO0
fileFetch.start(); 6),!sO?
} g""Ep
catch(Exception e){e.printStackTrace ();} B}J0d
J06D_'{
yG;@S8zC
} I]%Kd('
0es\ j6c
EeGTBVms
public static void main(String[] args) _j*a5fsPU
{ tns4e\
new TestMethod(); i0Rj;E=:]
} ZSr!L@S
} xUTTRJ(\
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