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)); <6d{k[7fz)
} +XU$GSw3(
for(int i=0;i<nEndPos.length-1;i++) xWC\954
{ 1jZDw~
nEndPos = nStartPos[i+1]; TS\A`{^T
} *3w/`R<\
nEndPos[nEndPos.length-1] = nFileLength; z/eU^2V
} FT|/WZR
} 9,iq"dQ
sx;V,"Y
R`I8Ud4=
//启动子线程 6nY )D6$JG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &J5-'{U|0
for(int i=0;i<nStartPos.length;i++) u7WTSL%
{ HKEop
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !#@4xeBPo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1cHSgpoJ
nStartPos,nEndPos,i); %S(#cf!HP
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $>S}acuC
fileSplitterFetch.start(); C*W.9
} 9sfB+]}h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \dp9@y[^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); yZj}EBa
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;qT!fuN;
nEndPos = " + nFileLength); (!XYH@Mz<w
// fileSplitterFetch[nPos.length-1].start(); }\`-G+i{W
'?vgp
1A`?y& Ll
//等待子线程结束 6]@|7|N>X
//int count = 0; fwnYzd3
//是否结束while循环 RAD4q"}k
boolean breakWhile = false; t[f9Z
PO1:9
S,wj[;cv4
while(!bStop) bG?WB,1
{ Dho[{xJ46
write_nPos(); S2At$47v
Utility.sleep(500); YaY;o^11/
breakWhile = true; !7Yt`l$$z
lt2Nwt0bv
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for(int i=0;i<nStartPos.length;i++) Rktn/Vi
{ <u x*r#a!d
if(!fileSplitterFetch.bDownOver) {d?4;Kd
{ ,#'o)O#
breakWhile = false; xnhDW7m
break; }(g+:]p-
} i)ES;b4
} HYI1 o/}
if(breakWhile) 764}yV>
break; f>wW}-
Il&"=LooZ
5uD#=/oV
//count++; jnU*l\,
//if(count>4) jOm&yX
// siteStop(); 02J6Pn3
} .J1Hg
0ez i?Um
aoakTi!}
System.err.println("文件下载结束！"); #8Id:56
} z!1/_]WJ,
catch(Exception e){e.printStackTrace ();} E-tNB{r@
} +Qi52OG
@8Q+=abz
*OGXu07 !
//获得文件长度 >QZt)<[
public long getFileSize() p^zEfLTU
{ d_WnK{
int nFileLength = -1; Wf`OyeRz
try{ LO$#DHPt
URL url = new URL(siteInfoBean.getSSiteURL()); ?%za:{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r"u(!~R
httpConnection.setRequestProperty("User-Agent","NetFox"); 'Qs3
%:be{Y6
RZ/+K=
int responseCode=httpConnection.getResponseCode(); Og;$P'U
if(responseCode>=400) C5sN[
{ '+q'H
processErrorCode(responseCode); sw qky5_K
return -2; //-2 represent access is error E/L?D
} P=SxiXsr$
h@>rjeY@
G5QgnxwP2
String sHeader; /nMqEHCyg
Vm1c-,)3
)ejXeg
for(int i=1;;i++) &PQ{e8w
{ e/HX,sf_g
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); LnRi+n[@7
//Utility.log(in.readLine()); A]SB c2
sHeader=httpConnection.getHeaderFieldKey(i); !7NzW7j
if(sHeader!=null) t1RwB23
{ 8#Z\}gGz
if(sHeader.equals("Content-Length")) %dk$K!5D0
{ Alk* "p
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l~6SR
break; e2hk
} C#?d=x
} b1>$sPJ+
else 4qSS<SqY
break; CO%O<_C
} (krG0S:0Q
} RH'F<!p
catch(IOException e){e.printStackTrace ();} *(SBl}f4l
catch(Exception e){e.printStackTrace ();} A$"$`)P!
#u=O 5%.
M4hN#0("4
Utility.log(nFileLength); fN*4(yw
ubCJZ"!
aXK%m
return nFileLength; EPd.atA
} U5ud?z()OA
f s"V'E2a
n,Mw# r?y
//保存下载信息（文件指针位置） @%@^5
private void write_nPos() %{VI-CQ
{ %"KWjwp
try{ l-h7ksRs
output = new DataOutputStream(new FileOutputStream(tmpFile)); "RJk7]p`*
output.writeInt(nStartPos.length); TcKKI
for(int i=0;i<nStartPos.length;i++) 7E6?)bgh
{ 2,e|,N"zN
// output.writeLong(nPos); |xgCV@
output.writeLong(fileSplitterFetch.nStartPos); 8H`l"
output.writeLong(fileSplitterFetch.nEndPos); j&G~;(DY
} W4rw;(\
output.close(); fi4/@tV?$L
} %/4_|@<'
catch(IOException e){e.printStackTrace ();} J%[N-
catch(Exception e){e.printStackTrace ();} S~(VcC$K
} -JO46 #m
o(SJuZC/U
Z-p^3t'{
//读取保存的下载信息（文件指针位置） &$z1Hz+l
private void read_nPos() a3 _0F@I
{ g$T_yT''
try{ >93{=+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); qF6%XKbh=
int nCount = input.readInt(); =cKk3kJC
nStartPos = new long[nCount]; C<=p"pWw
nEndPos = new long[nCount]; [Z Gj7
for(int i=0;i<nStartPos.length;i++) Cg\)BHv~
{ ieF 0<'iF
nStartPos = input.readLong(); .-26 N6S
nEndPos = input.readLong(); dSOn\+
} S+xGHi)
input.close(); ? A#z~;X@
} :pjK\
catch(IOException e){e.printStackTrace ();} eD1MP<>h
catch(Exception e){e.printStackTrace ();} p|8Fl
} rHdP4:n
WI4_4
(X7yNIPfA
private void processErrorCode(int nErrorCode) HY|SLk/E
{ ,Y5 4(>>%
System.err.println("Error Code : " + nErrorCode); #<>E+r+
} zr9Pm6Rl
&E'>+6
RkV3_c
//停止文件下载 Sm_:SF!<D6
public void siteStop() ^A<.s_
{ h=y(2xA
bStop = true; :Du{8rV
for(int i=0;i<nStartPos.length;i++) u]-El}*[
fileSplitterFetch.splitterStop(); K~%5iVO~\
U"kK]Stk<
1'pQ,
} Cv7RCjMw
} ~HI0<;r=eL
//负责部分文件的抓取 s ;Nu2aOp7
**FileSplitterFetch.java XUNgt(OGR'
*/ 5h^qtK
package NetFox; (9_e>2_
$`{q =
]"vdC}
import java.io.*; iw;Alav"x
import java.net.*; AezXou&
';!UJWYl
"m)O13x
public class FileSplitterFetch extends Thread { .7Bav5 ;
kV%y%l(6
,^66`C[G
String sURL; //File URL P3FpU<OBwp
long nStartPos; //File Snippet Start Position 2m}]z.w#
long nEndPos; //File Snippet End Position &|FG#.2yw
int nThreadID; //Thread's ID yXl.Gq>]{
boolean bDownOver = false; //Downing is over s/^=WV
boolean bStop = false; //Stop identical W]7?;#Hpk
FileAccessI fileAccessI = null; //File Access interface /!8:/7r+W
F qyJ*W\1
by ee-BU
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException F+-MafN7Y
{ 2p.+C35c=j
this.sURL = sURL; 8>+eGz|
this.nStartPos = nStart; dM.Ow!j
this.nEndPos = nEnd; $4)guG)
nThreadID = id; m,fr?d/;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 QncS&
} |8+rUFkU8
L| qY
ArKrsI#H-
public void run() zMg^2{0L
{ ~2;y4%K
while(nStartPos < nEndPos && !bStop) = $Yk8,
{ OVK(:{PwS
RaqrVC
{lw ec"{
try{ udr'~,R
URL url = new URL(sURL); U.)eJ1a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u-cC}DP
httpConnection.setRequestProperty("User-Agent","NetFox"); tXGcwoOB
String sProperty = "bytes="+nStartPos+"-"; `u)V9{
httpConnection.setRequestProperty("RANGE",sProperty); 1fG@r%4
Utility.log(sProperty); uB!P>v6
O4URr
t)b>f~
InputStream input = httpConnection.getInputStream(); :P'5_YSi
//logResponseHead(httpConnection); TJa%zi
z$,hdZ]
(VRnv
byte[] b = new byte[1024]; a[#BlH
int nRead; tjL#?j
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) wQ95tN
{ yZ6X$I:C
nStartPos += fileAccessI.write(b,0,nRead); PSvRO%&
//if(nThreadID == 1) nI` 1@vB&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @72G*u\Wz
} h<jIg$rA
<m\TZQBD
v2SsfhT
Utility.log("Thread " + nThreadID + " is over!"); S+ x[1#r
bDownOver = true; U_04QwhK7
//nPos = fileAccessI.write (b,0,nRead); A]slssE+
} N* QI>kzU
catch(Exception e){e.printStackTrace ();} #`EMK
} L>*|T[~
} ;!Mg,jlQ
ttxOP
hTqJDP"&F
//打印回应的头信息 +%^xz 1m
public void logResponseHead(HttpURLConnection con) EkPSG&6RZ
{ R``qQ;cc
for(int i=1;;i++) WfI~l)
{ Z r*ytbt
String header=con.getHeaderFieldKey(i); FL}8h/
if(header!=null) @bE?WXY
//responseHeaders.put(header,httpConnection.getHeaderField(header)); H$HhB8z3
Utility.log(header+" : "+con.getHeaderField(header)); 8Aqe'2IH=
else ^Y!`wp2vn
break; w-m2N-"='
} |hAGgo/03
} (yVI<Os{a
dv:&N
jk?(W2c#{
public void splitterStop() <aS1bQgaU
{ AUd}) UR
bStop = true; =^{+h>#s@
} {M5IJt"{4b
dzap]RpB
^8*.r+7p
} P=GM7
/ ffWmb_4
R2{X? 2|$
/* LNWp$"
**FileAccess.java l,3tU|V
*//文件访问(定位，写) uW|y8 BP $
package NetFox; gfHlY Q]
import java.io.*; #-O4x`W>
w\a#Bfcv
t `oP;
public class FileAccessI implements Serializable{ $MR4jnTT
:JmNy<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Yy5F'RY
RandomAccessFile oSavedFile; ~5zhK:7c
long nPos; V"z0]DP5~
9lwg`UWl,
mD:!"h/
public FileAccessI() throws IOException '>8N'*
{ N~_gT Jr~P
this("",0); :8FH{sqR
} z%z$'m
+xa2e?A%L
YrX{,YtiX
public FileAccessI(String sName,long nPos) throws IOException G5Nub9_*X
{ J=Z"sU=
oSavedFile = new RandomAccessFile(sName,"rw"); =>Efrma
this.nPos = nPos; 92R{V%)G
oSavedFile.seek(nPos); 7UiU3SUcg
} K} @q+
{1mD(+pJ{
"|H0 X#
public synchronized int write(byte[] b,int nStart,int nLen) %vI]"a@
{ &+p07
int n = -1; d#su
try{ 8^~]Ym:
oSavedFile.write(b,nStart,nLen); F~6[DqF\|
n = nLen; W0Vjs|/
} 78kk"9h'
catch(IOException e) x[E`2_Ff0
{ U8z,N1]r*`
e.printStackTrace (); YZd4% zF
} x1Uj4*Au
YR>xh2< 9
fQ@["b
return n; o5d)v)Rx=
} pE#0949
& |r)pl0$
S!uyplYKF
} ]`x~v4JU
l?d*g&
xK f+.6 wz
/* gw-l]@;1
**SiteInfoBean.java _~r>C
*/ fjf\/%
package NetFox; *e=e7KC6kI
RN;Tqq):
6K6ihR!d
public class SiteInfoBean { V*)gJg
H~&'`h1
!^%b|=[
private String sSiteURL; //Site's URL %%#zO Z
private String sFilePath; //Saved File's Path 5E]I
private String sFileName; //Saved File's Name %NuS!v>
private int nSplitter; //Count of Splited Downloading File gBN;j
7_LE2jpC,5
Lgy}Gm8u5
public SiteInfoBean() }6\p7n
{//nSplitter的缺省值为5 3Dy.mtP
//default value of nSplitter is 5 5,A/6b
this("","","",5); 2KU[Yd
} F C"dQ
Y,{Xv
K-/fq=z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) gC?k6)p$N
{ @uHNz-c
sSiteURL= sURL; 16AYB17
sFilePath = sPath; /PO5z7n0J
sFileName = sName; 9ItsK
this.nSplitter = nSpiltter; ^#Shs^#
tkA '_dcIC
cP-6O42
} VHy$\5oYg
Ma$b(4dB
~<aCn-h0
public String getSSiteURL() a`}HFHm\2,
{ :)&_
return sSiteURL; FXIQS'
} ^ `!6Yax?
UGIyNMY
J::dY~@
public void setSSiteURL(String value) { Uh/ ~zu
{ ;Q ]bV52
sSiteURL = value; ]P-;]*&=
} h[Hw9$31
&N,c:dNe
,+f'%)s_x
public String getSFilePath() KV Mm<]Z
{ EBJaFz'
return sFilePath; Rh%x5RFFc
} P*_Q8I)Y
y'{0|Xj
6j0!$q^
public void setSFilePath(String value) 8[eH8m#~$
{ ZT!DTb B
sFilePath = value; l =#uy
} A@GyKx%x$
`6'fX[j5
^;M!u8[
public String getSFileName() e4t'3So
{ b}Jcj
return sFileName; 7 'N&jI
} rTQrlQ:@
r'"H8>UZ%
uSH.c>
public void setSFileName(String value) (JOge~U
{ 1aKY+4/G
sFileName = value; -(dc1?COi
} &GX pRo
^+I{*0{/[
!fY'^Ya?
public int getNSplitter() :9.ik
{ t!v#rn[
return nSplitter; ]wZG4A
} PXWBc\
0P z"[
2 g,UdG
public void setNSplitter(int nCount) zl$'W=[rFs
{ yqZKn=1:
nSplitter = nCount; b8(94t|;U
} #Fq6-]y1")
} {eL XVNR7R
;V@o 2a
G7b>r
/* &G:#7HX@-
**Utility.java ;>bcI).
*/ YFeF(k!!n
package NetFox; }}@xx&
id'E_]r
J#"@~Q+a`@
public class Utility { ~0eJ6i
r1f##
!c/G'se
public Utility() s'RE~,
{ XX+%:,G
Ny\p$v "p
G[GSt`LVS`
} X)P9f N~7
q&#f#Ou
//线程睡眠 pKMy:j
public static void sleep(int nSecond) f!AcBfaLr
{ =c:K(N qL
try{ 1$H*E~
Thread.sleep(nSecond); Z$"E|nRN
} qX>mOW^gT8
catch(Exception e) ')zdI]@M
{ X|++K;rtfE
e.printStackTrace (); <'f+nC=2
} +G)L8{FY(
} hX;JMQ915
Em?bV(
//日志 `saDeur#X
public static void log(String sMsg) >|IUjv2L
{ >NDI<9<'0}
System.err.println(sMsg); .'aW~WR
} hj[&.w
u 6A!Sw
j\@Ht~G
public static void log(int sMsg) k/srT<
{ _P,3~ ;
System.err.println(sMsg); xA/Ein0
} oK\{#<gCZ
} ai0am
Q*&k6A"jx
3 vr T`
/* /r2*le (H
**TestMethod.java $I}7EI
*/ `3GYV|LeQ
package NetFox; 3HCH-?U5
<u`m4w
Q0l[1;$#
public class TestMethod { {{N*/E^
@~1}n/
3M~*4
public TestMethod() J?DJA2o
{ ///xx/weblogic60b2_win.exe 4TX~]tEyky
try{ Ts)ox}rYVm
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Y~,ZBl,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?Pbh&!
SiteFileFetch fileFetch = new SiteFileFetch(bean); o>~xrV`E
fileFetch.start(); m}`!FaB #
} nz+k ,
catch(Exception e){e.printStackTrace ();} nymro[@O~
N#C,q&;
'qoDFR\v
} t:$^iUrx
~IQ3B$4H&
{XR3L'X
public static void main(String[] args) NW?.Ge.!P
{ -0P(lkylf
new TestMethod(); E)ne z
} N./l\NtZ
} :^bjn3b
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