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)); &xo_93
} W4%I%&j
for(int i=0;i<nEndPos.length-1;i++) 5/F1|N4
{ @SjISZw_
nEndPos = nStartPos[i+1]; zR_ "
} s!:'3[7+
nEndPos[nEndPos.length-1] = nFileLength; ><V<}&:y$(
} $M5iU@A
} M+j V`J!
j^;f {0f
oCg|* c|+
//启动子线程 Y``50{7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; xAbx.\
for(int i=0;i<nStartPos.length;i++) 1YV ;pEw3w
{ e{EKM4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wj!YYBH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), A=JPmsj.
nStartPos,nEndPos,i); lD)ZMaaS3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Hb55RilC
fileSplitterFetch.start(); D_]4]&QYT
} 4 3V{q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), & Xm!i(i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <'N"GLJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mE=%+:o.
nEndPos = " + nFileLength); mhVdsa
// fileSplitterFetch[nPos.length-1].start(); [1nfSW
o-a\T
d0``:
//等待子线程结束 8JYU1Ew
//int count = 0; :d}I`)&
//是否结束while循环 .;}vp*
boolean breakWhile = false; UCV1{
!k@(}CN_*
GVR/p
while(!bStop) L|ZxB7xk
{ ]dIcW9a
write_nPos(); Nk?eVJ)
Utility.sleep(500); opsjei@
breakWhile = true; xl2;DFiYt
%])U(
'tvX.aX2
for(int i=0;i<nStartPos.length;i++) cQ}3? v
{ 1i3;P/
if(!fileSplitterFetch.bDownOver) v+d} _rCT
{ 7"Qj(N
breakWhile = false; ZDny=&>#
break; K93L-K^J
} %4'<0
} qJ(XW N H
if(breakWhile) yUnNf 2i
break; H j [!F%
K Q^CiX
F3nYMf
//count++; =sZ58xA
//if(count>4) )hG4,0hv&
// siteStop(); .ni<'
} !aQb Kp
AS4mJ UU9
Lmsc~~
System.err.println("文件下载结束！"); 8]h~jNku
} 5tx!LGOK
catch(Exception e){e.printStackTrace ();} @n,V2`"
} ~'1gX`o:
&A}hx\_T
B']-4X{SGa
//获得文件长度 .fFXH
public long getFileSize() 4j|IG/m
{ y'L7o V?L9
int nFileLength = -1; mHe[ NkY6
try{ ba-4V8w
URL url = new URL(siteInfoBean.getSSiteURL()); !E7JDk''@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {ooztC
httpConnection.setRequestProperty("User-Agent","NetFox"); FD'yT8]"
cl04fqX
#ZkT![`
int responseCode=httpConnection.getResponseCode(); !,lk>j.V
if(responseCode>=400) 9]C%2!Ur,
{ "hid3"G
processErrorCode(responseCode); AjVX
return -2; //-2 represent access is error e dTFk$0
} iX%9$Bft<
7f] qCZ<0V
+[vIocu
String sHeader; uwl_TDc>%
JAx0(MZO
x52#md-Z
for(int i=1;;i++) fHK.q({Qc
{ &R5zt]4d&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); A=W:}szt]
//Utility.log(in.readLine()); .Ht;xq
sHeader=httpConnection.getHeaderFieldKey(i); }#r awVe=
if(sHeader!=null) {x{~%)-
{ :%_\!FvS
if(sHeader.equals("Content-Length")) Gsn$r(m{K
{ p<[MU4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); t)|~8xpP
break; <@Z`<T6
} R1$s1@3I|
} E$.fAIt
else UpaF>,kM
break; 71n3d~!O>
} qCkC2Fy(
} v]Fw~Y7l!
catch(IOException e){e.printStackTrace ();} "%}24t%
catch(Exception e){e.printStackTrace ();} GXaPfC0-y
@r&*Qsf|
8 XQo
Utility.log(nFileLength); N TcojA{V$
p$=Z0p4%LL
KFgq3snH
return nFileLength; YdDP;, DA
} VBUrtx:
GQ(*k)'a
OxQ5P;O
//保存下载信息（文件指针位置） &V|kv"Wwj
private void write_nPos() w_h{6Kc<
{ cgnMoBIc
try{ jB<B_"
output = new DataOutputStream(new FileOutputStream(tmpFile)); oN2#Jh%dH
output.writeInt(nStartPos.length); Q5c3C&$6
for(int i=0;i<nStartPos.length;i++) 0qINa:Ori
{ >?O?U=:<
// output.writeLong(nPos); IClw3^\l
output.writeLong(fileSplitterFetch.nStartPos); !YPwql(
output.writeLong(fileSplitterFetch.nEndPos); 7Kf
} :wq][0)
output.close(); oam$9 q
} zLgc j(;
catch(IOException e){e.printStackTrace ();} !2kM
catch(Exception e){e.printStackTrace ();} fMIRr5
} k%3)J"|/
+ -uQ] ^n
<6Y|vEo!N
//读取保存的下载信息（文件指针位置） _\=x A6!
private void read_nPos() B(WmJ6e
{ ;>uB$8<_7
try{ B}S+/V` Y5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3[j,d]\|
int nCount = input.readInt(); o}DRp4;Ka
nStartPos = new long[nCount]; _dELVs7OL
nEndPos = new long[nCount]; Iprt ZqiL
for(int i=0;i<nStartPos.length;i++) T+^Sa J
{ v%$l(
nStartPos = input.readLong(); ht*N[Pi4;
nEndPos = input.readLong(); _&~l,%)&
} ,hH c -%-
input.close(); i=L 86Ks
} {yv_Ni*6!
catch(IOException e){e.printStackTrace ();} I{Ip
catch(Exception e){e.printStackTrace ();} :tBe/(e4#
} )RN3Oz@H
=;+gge!?bB
O|S,="h"}
private void processErrorCode(int nErrorCode) L(bDk'zi
{ O:sqm n
System.err.println("Error Code : " + nErrorCode); ] )iP?2{
} ~5&B#Sm[G
#K0/ >W
)!kt9lK
//停止文件下载 tA^+RO4
public void siteStop() ZJF"Yo
{ %%F,G
bStop = true; Z^]jy>dj
for(int i=0;i<nStartPos.length;i++) 'z^'+}iyv
fileSplitterFetch.splitterStop(); Ypl;jkHP
#8sy QWlG
=@ acg0
} >|, <9z`D
} ~;jgl_5?b
//负责部分文件的抓取 7m ou
**FileSplitterFetch.java vp2w^/])u
*/ -.r"|\1X
package NetFox; TFG? EO
D_?Tj
ZR -RzT1
import java.io.*; KTt+}-vP^
import java.net.*; !zt>& t
i6P}MtC1
g4=C]\1
public class FileSplitterFetch extends Thread { YO-B|f
e,{k!BXU#'
yKuZJXGVo
String sURL; //File URL '$Z@oCY#
long nStartPos; //File Snippet Start Position A +=#
long nEndPos; //File Snippet End Position VH4wsEH]
int nThreadID; //Thread's ID z{&Av
boolean bDownOver = false; //Downing is over ZJW8S
boolean bStop = false; //Stop identical uB^"A ;0v
FileAccessI fileAccessI = null; //File Access interface %19~9Tw
pdm(7^
z:Tj0<A'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException n-2!<`UFX
{ tH&eKM4G
this.sURL = sURL; tvf5b8(Y-
this.nStartPos = nStart; ?FNgJx*\S
this.nEndPos = nEnd; y{&%]Fq <5
nThreadID = id; k-a1^K3
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I{[}1W3]W
} 5k@T{
g)\Tex<
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public void run() fPHV]8Ft|
{ *^Zt)U1$|
while(nStartPos < nEndPos && !bStop) }cI-]|)|2
{ ?mM:oQH+>
X31%T"
0C.5Qx
try{ sxA]o|
URL url = new URL(sURL); \pkK >R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cuH5f}oc
httpConnection.setRequestProperty("User-Agent","NetFox"); ppRA%mhZ
String sProperty = "bytes="+nStartPos+"-"; 5Pq6X
httpConnection.setRequestProperty("RANGE",sProperty); 9od c :
Utility.log(sProperty); N<@K(?'
#'O9Hn({
H{yBDxw
InputStream input = httpConnection.getInputStream(); "!(@MfjT
//logResponseHead(httpConnection); p>kny?AJ
*J]p/<> {
AA)pV-
byte[] b = new byte[1024]; "9dZ z/{
int nRead; eaNfCXHDN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) wEl7mg !
{ -W.-m2:1
nStartPos += fileAccessI.write(b,0,nRead); 3 ^x&G?)
//if(nThreadID == 1) I$S*elveG
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jl}!UG
} Xs|d#WbX
K|\0jd)N
n^$Q^[:Z
Utility.log("Thread " + nThreadID + " is over!"); 0[fBP\H"Wr
bDownOver = true; @`+\vmfD
//nPos = fileAccessI.write (b,0,nRead); ^7ID |uMr
} shL_{}
catch(Exception e){e.printStackTrace ();} [qV/&t|O*h
} c%O97J.5b
} aCH;l~+U
c$)>$&([
!( +M
//打印回应的头信息 ]mi\Y"RO
public void logResponseHead(HttpURLConnection con) cAGM|%
{ bf=\ED^
for(int i=1;;i++) hrD2-S
{ Xjxa 2D
String header=con.getHeaderFieldKey(i); !]}C!dXd
if(header!=null) f3n^Sw&Q(Q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t5_76'@cX
Utility.log(header+" : "+con.getHeaderField(header)); Z ztp %2c
else y${`W94
break; -hfkF+=U'
} suIYfjh
} o<p4r}*AVJ
%-fS:~$
A@?-"=h}
public void splitterStop() p<h(
{ bC"h7$3
bStop = true; Ac{TqiIv
} ^b~ZOg[p
_t;^\"\
-IVWkA)7
} OGLA1}k4
G5OGyQp
(VmFYNt&
/* mJd8?d
**FileAccess.java "[k>pzl6
*//文件访问(定位，写) yMM2us#*+q
package NetFox; G;#xcld
import java.io.*; DF-PBVfpu
Vv5T(~
OAFxf,b
public class FileAccessI implements Serializable{ 6< -Cpc
u\iKdL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 oxeIh9 E
RandomAccessFile oSavedFile; gBWr)R
long nPos; =Ez@kTvOs
W5Jy"]^I
3TeRZ=2:*x
public FileAccessI() throws IOException 9bRUN<
{ E}F-*go
this("",0); 6{udNv X
} 5+Tx01)
8[t*VIXI
hT_Q_1,
public FileAccessI(String sName,long nPos) throws IOException k^ fW/
{ *' es(]W
oSavedFile = new RandomAccessFile(sName,"rw"); q9VBK(,X
this.nPos = nPos; :/6aBM?
oSavedFile.seek(nPos); v8'XchJ
} .}eM"Kv
.waj.9&[l
R}3th/qf
public synchronized int write(byte[] b,int nStart,int nLen) K0o${%'@7
{ MK! @ND
int n = -1; C8qSoO4Z
try{ .X(qs1
oSavedFile.write(b,nStart,nLen); p/u
n = nLen; ek/zQM@%
} lb*;Z7fx<'
catch(IOException e) ">h$(WCK
{ thX4-'i
e.printStackTrace (); 90Sras>F
} b{ A/M#=
-$#2?/uqC
Voq/0,d
return n; J(~1mIJjC
} z[Qe86L
_ MB/p
(E,[Ad,$
} Unq~lt%2
nFI<Te^)
l O*
/* (M u;U!M"P
**SiteInfoBean.java vg@5`U`^h
*/ 9C Ki$L
package NetFox; ,JbP~2M~%
m:~y:.
.X)Wb{7
public class SiteInfoBean { Ay^P#\VZ
-#G>`T~
,Csjb1
private String sSiteURL; //Site's URL P*%P"g
private String sFilePath; //Saved File's Path <tsexsw
private String sFileName; //Saved File's Name i|,}y`C#
private int nSplitter; //Count of Splited Downloading File H"Hl~~U
Tj!\SbnA[
3fX_XH1Q
public SiteInfoBean() N7}3?wS
{//nSplitter的缺省值为5 7B5b +
//default value of nSplitter is 5 PBEi"`i
this("","","",5); U1fqs{>
} CK|AXz+EN
#cW:04
xX{Zh;M&[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]mNsG0r6
{ Oi$1maxT
sSiteURL= sURL; [ybK
sFilePath = sPath; R^$EnrY(<
sFileName = sName; =b1 y*?
this.nSplitter = nSpiltter; X&rsWk
<4@8T7
)Spa F)N8
} D^p)`*
*>Bew
PQYJnx}
public String getSSiteURL() WD[jEWMV7D
{ luac
return sSiteURL; |f1^&97=+
} 2>9..c
FjiIB1 T
s`[V{1m,
public void setSSiteURL(String value) dWi.V?K4z
{ L*4=b (3
sSiteURL = value; X_bB6A6
} 8WpNlB+:{
{x..> 4
q&NXF(
public String getSFilePath() {-]K!tWda
{ ;p<BiC$b
return sFilePath; iyUnxqP
} ,+C?UW
w}(pc}^U
=,qY\@fq
public void setSFilePath(String value) <pKOFN%m
{ -'WR9M?fq
sFilePath = value; >XRf= :3
} n+<
,VUOsNN4\
KIWHn_ :
public String getSFileName() xdaq` ^Bbt
{ 2VX9FDrnk
return sFileName; 1~2+w]-kU
} #}~?8/h!
R*k;4*1u
z-"P raP
public void setSFileName(String value) Q.V@Sawe5
{ @<4U &
sFileName = value; `jhbKgR[
} o"P)(;
I*a.!/$)
Hl{ul'o
public int getNSplitter() ft0d5n!ui4
{ ,Tx38
return nSplitter; ZdPqU\G^q
} oz|+{b}%
Z R~2Y?Wt9
"Z&_*F.[O
public void setNSplitter(int nCount) _pvt,pW
{ XMxm2-%olP
nSplitter = nCount; C+t|fSJ
} Z3u6m0!
} <RH%FhT
Su +<mW
b%C7 kL-
/* U!BZsVx
**Utility.java ?LvU7
*/ [{vX*q 3B
package NetFox; =W"T=p*j
!kh:zTP
<9$Pl%:
public class Utility { +I*a=qjq
u'T>Y1I
3{ea~G)[9
public Utility() W>b\O">
{ 3(*vZ
i_`Po%
Zba<|C
} LCHw.
Pe11azJ
//线程睡眠 ]]_c3LJ2`
public static void sleep(int nSecond) dww4o~hO
{ FS!vnl8`
try{ or7l}X
Thread.sleep(nSecond); *8u<?~9F
} a%an={
catch(Exception e) 5~#oQ&
{ w-@6qMJ
e.printStackTrace (); ye}86{l
} J~ *>pp#U
} G#E8xA"{/
IkGM~3e
//日志 0/%RrE
public static void log(String sMsg) U`)d `4"
{ tpgD{BY^wJ
System.err.println(sMsg); b`;&o^7gMO
} g]?>6 %#rA
,d^HAg^j
<<@F{B7h
public static void log(int sMsg) Ca/N'|}^
{ +*eVi3
System.err.println(sMsg); <0Gk:NB,
} -xyY6bxL
} ybIqn0&[
iUqD>OV
Fd%JF#Hk
/* T=g2gmo9
**TestMethod.java PbV1FB_
*/ 01]W@\(
package NetFox; F"23vG>3
N~?#Qh|ZnU
jPc,+?
public class TestMethod { Y|KT3
Cw5B p9
nLrCy5R:
public TestMethod() @j(2tJ,w
{ ///xx/weblogic60b2_win.exe 6"r _Y7%
try{ :/>Zky8,k
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {aU|BdATI
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (H]NL
SiteFileFetch fileFetch = new SiteFileFetch(bean); A9GSeW<
fileFetch.start(); 9R[PpE''
} yRp&pUtb
catch(Exception e){e.printStackTrace ();} _0iV6Bj
<e@4;Z(h04
lpbcpB
} 4#B56f8
wkJ@#jD*[
g/w<T+v
public static void main(String[] args) iBKH\em/
{ od&wfwk(
new TestMethod(); dI%Nwl%
} _.m|Ml,`{
} D'UIxc8
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