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)); eC6>yD6D
} \fK47oV
for(int i=0;i<nEndPos.length-1;i++) |P~O15V*Q
{ K`Bq(z?/
nEndPos = nStartPos[i+1]; nTys4R
} 3s`V)aXP
nEndPos[nEndPos.length-1] = nFileLength; =Kc|C~g
} EqD^/(,L2
} j?:`-\w5
4llD6&%
J?UA:u
//启动子线程 W/ g|{t[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e9CP802#2
for(int i=0;i<nStartPos.length;i++) ^W Y8-6
{ 0 kf(g156
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +"cRhVR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), + a-wv
nStartPos,nEndPos,i); #K=b%;>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N;-/wip
fileSplitterFetch.start(); 59{;VY81
} >u=%Lz"J
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -7>^ rR V
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `"a? a5]k
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8P,l>HA
nEndPos = " + nFileLength); WD15pq l
// fileSplitterFetch[nPos.length-1].start(); K;oV"KRK
o]Z _@VI
gtD
//等待子线程结束 t< sp%zXZ
//int count = 0; w&p~0cA~
//是否结束while循环 _*s~`jn{H
boolean breakWhile = false; NWEhAj<w
UT3bd,,
\un sh^M
while(!bStop) i[$-_
{ .#*D!;f
write_nPos(); pw@`}cM=
Utility.sleep(500); ]\A1mw-T
breakWhile = true; w#*/y?"D
_ XE;-weE
`-VG ?J
for(int i=0;i<nStartPos.length;i++) w6vLNX
{ wJ6_I$>
if(!fileSplitterFetch.bDownOver) :qxm !P
{ RX:R*{]-
breakWhile = false; 1p8:.1)q
break; ;0IvF#SJ(.
} `9/0J-7*
} 'KH lrmnr
if(breakWhile) .iFViVZC
break; '%R<"
~gP7s_qr{
qQ^d9EK'?~
//count++; tcZa~3.
//if(count>4) &=G)NeT_
// siteStop(); Te# ]Cn|
} PPEq6}
$=/rGpAk
Qh*)pt]n
System.err.println("文件下载结束！"); G'u|Q mb1
} 'e F%
catch(Exception e){e.printStackTrace ();} `M&P[.9Pz
} !X-9Ms}(d
j(j#0dXLh
\.o=icOx
//获得文件长度 # Mu<8`T-
public long getFileSize() ^w.]Hd2
{ 4Rx~s7l
int nFileLength = -1; 6Lb{r4^
try{ <PX.l%
URL url = new URL(siteInfoBean.getSSiteURL()); z<!O!wX_aI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >Iuzk1'S
httpConnection.setRequestProperty("User-Agent","NetFox"); G~"z_ (
u$C\E<G^
h\(B#SN
int responseCode=httpConnection.getResponseCode(); :$NsR*Cq*9
if(responseCode>=400) GQb i$kl
{ eH %Ja[
processErrorCode(responseCode); I!P4(3skAB
return -2; //-2 represent access is error 8) HBh7/
} c&E]E(
2`EVdl7B]
1B 5:s,Oyj
String sHeader; A_Rrcsl4
tAERbiH
Lbcy:E*g
for(int i=1;;i++) k@yh+v5
{ ,]ga[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S<"oUdkz
//Utility.log(in.readLine()); {Ur7#h5
sHeader=httpConnection.getHeaderFieldKey(i); gljo;f:
if(sHeader!=null) w8p8 ;@
{ GF*>~_Yr
if(sHeader.equals("Content-Length")) :5J_5,?;`
{ p}uncIod
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); pr_>b`p6
break; 9YD\~v;x
} eeM?]J-
} 8] `Ru5nd
else \Wr,<Y
break; }9^@5!qX
} {{\ce;hN
} cMaOM}mS
catch(IOException e){e.printStackTrace ();} 7\Co`J>p2
catch(Exception e){e.printStackTrace ();} ,[* ;UR
*$S#o#5
,!Q]q^{C:W
Utility.log(nFileLength); QOH<]~3J
Ke!'gohv
X3',vey
return nFileLength; dxK9:IX
} (,B#t7ka
Ird|C[la
2s\BY%XY
//保存下载信息（文件指针位置） /,2rjJ#b
private void write_nPos() ;'0=T0\
{ D/CIA8h3
try{ .fp&MgiQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5pfYEofK[
output.writeInt(nStartPos.length); H>XFz(LWh
for(int i=0;i<nStartPos.length;i++) XRxj W
{ `:p1&OS
// output.writeLong(nPos); KnGTcoXg_
output.writeLong(fileSplitterFetch.nStartPos); tlQC6Fb#
output.writeLong(fileSplitterFetch.nEndPos); >&Y-u%}U
} U<^F4*G
output.close(); U\zD,<I9
} o:~LF6A-
catch(IOException e){e.printStackTrace ();} bWmw3w
catch(Exception e){e.printStackTrace ();} eM2|c3/
} 'RbQj}@x
* ?]~ #
=^tA_AxVw
//读取保存的下载信息（文件指针位置） iX"C/L|JN
private void read_nPos() U>a\j2I
{ Jxa4hM0
try{ Yf}xwpuLk
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g9~]s9
int nCount = input.readInt(); pDl3!m
nStartPos = new long[nCount]; D=+NxR[
nEndPos = new long[nCount]; IeP WOpj3
for(int i=0;i<nStartPos.length;i++) TB!(('
{ *2e!M^K<
nStartPos = input.readLong(); QI_4*
nEndPos = input.readLong(); sOpep
} l63hLz
input.close(); BUsV|e\
} _las;S'oa
catch(IOException e){e.printStackTrace ();} H43MoC
catch(Exception e){e.printStackTrace ();} }Wh6zT)
} ,R2U`EO;
LT VF8-v
b~w=v_[(I
private void processErrorCode(int nErrorCode) mbxbEqz
{ }D;WN@],
System.err.println("Error Code : " + nErrorCode); 2oCkG~j
} _zMgoc7
=Vw 5q},3
U*)m',
//停止文件下载 oD.r`]k
public void siteStop() _S`o1^Ad
{ CU)|-*uiK
bStop = true; -7{$Vj
for(int i=0;i<nStartPos.length;i++) 'hqBo|
fileSplitterFetch.splitterStop(); &JP-O60
5Qh?>n>*
!mMpb/&&S
} bB}5U@G|
} X3%Ic`Lq#
//负责部分文件的抓取 Ul+Mo&y-
**FileSplitterFetch.java T'H::^9:E
*/ n, i'Dhzk
package NetFox; N?P%-/7
oCS2E =O&
nNt1C
import java.io.*; Zd:Taieh@
import java.net.*; ep/Y^&$M
04U")-\O
Y>+y(ck
public class FileSplitterFetch extends Thread { N!2Rl
nh>K`+>co
cV{o?3<:B
String sURL; //File URL F4L;BjnJ
long nStartPos; //File Snippet Start Position \Ae9\Jp8M
long nEndPos; //File Snippet End Position x1&W^~
int nThreadID; //Thread's ID 6CbxuzYer
boolean bDownOver = false; //Downing is over $~;D9
boolean bStop = false; //Stop identical -E"GX
FileAccessI fileAccessI = null; //File Access interface /X'(3'a
G 2!xPHz
\QE)m<GUe
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^= 0m-/
{ ]X Z-o>+,
this.sURL = sURL; `;l.MZL!
this.nStartPos = nStart; .iX# A<E}
this.nEndPos = nEnd; *+)AqKP\Kv
nThreadID = id; ={>Lrig:l
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \*f;Xaa
} e[_m<e
Q6'x\
rgmF:C
public void run() c(;a=n(E#
{ DwHF[]v'
while(nStartPos < nEndPos && !bStop) YuZ"s55zU{
{ N- H^lqD
l 'DsZ9y@2
3"n\8#X{
try{ ,L bBpi=TJ
URL url = new URL(sURL); +l3=3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0sca4G0{
httpConnection.setRequestProperty("User-Agent","NetFox"); 10!wqyj&
String sProperty = "bytes="+nStartPos+"-"; ,<BbpIQ2o
httpConnection.setRequestProperty("RANGE",sProperty); *}k;L74|
Utility.log(sProperty); ^sN (
yeDsJ/L
^V$Ajt
InputStream input = httpConnection.getInputStream(); ivDGZI9
//logResponseHead(httpConnection); M])dJ9&e
FIxFnh3~
]I3!fEAWR
byte[] b = new byte[1024]; JRCrZW}
int nRead; <S?ddp2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) < -W*$?^
{ MUfG?r\t
nStartPos += fileAccessI.write(b,0,nRead); +)o}c"P!
//if(nThreadID == 1) `\Hf]b
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A+hT3;lp
} (jU6GJRP
H"ZZ.^"5FV
;22oY>w
Utility.log("Thread " + nThreadID + " is over!"); m3Il3ZY.
bDownOver = true; @2'Mt}R>
//nPos = fileAccessI.write (b,0,nRead); 2{|h8oz
} L_=3<nE
catch(Exception e){e.printStackTrace ();} T^J>ZDA
} 0d8%T<=J
} GFr|E8
u#}[ZoI
x#Sqn#
//打印回应的头信息 F 8B#}%JE
public void logResponseHead(HttpURLConnection con) (Jz;W<E
{ pPd#N'\*
for(int i=1;;i++) i[wb0yL
{ yR(x+Gs{]
String header=con.getHeaderFieldKey(i); a!O0,y
if(header!=null) Q0EiEX)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~ vqa7~}m
Utility.log(header+" : "+con.getHeaderField(header)); )iFJz/n>
else /cU<hApK
break; W`c'=c
} HRB<Y mP@
} yX~v-N!X
s%<eD
[l,Ei?
public void splitterStop() 3}e%[AKh
{ ^o7;c[E`
bStop = true; M)SEn/T-
} 8#vc(04(
:9k Ty:
fW?o@vlO
} N<~ku<nAU
O{#=d
F_CYYGZ
/* +SwR+H)?
**FileAccess.java JQ"U4GVp
*//文件访问(定位，写) iX)%Q
package NetFox; CHz+814
import java.io.*; &RfC"lc
ocs+d\
TqnTS0fx
public class FileAccessI implements Serializable{ >y,-v:Vy
%n*-VAfE\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 D-c`FG'
RandomAccessFile oSavedFile; 'q`^3&E
long nPos; cFJY^A
1YH+d0UGn
MG.` r{5
public FileAccessI() throws IOException Hro-d1J7
{ Dd\jHF>u
this("",0); 9Q"'"b*?z
} >3Eo@J,?d
I"GB<oB
EVGt 5z
public FileAccessI(String sName,long nPos) throws IOException +llR204
{ :8OZ#D_Hl
oSavedFile = new RandomAccessFile(sName,"rw"); P?k0zwOlBl
this.nPos = nPos; >Z5gSs0
oSavedFile.seek(nPos); :\|SQKD
} 9E6_]8rl
`E>1>'
Ig f&l`\
public synchronized int write(byte[] b,int nStart,int nLen) RNe^; B
{ 76`8=!]R
int n = -1; }9FSO9*&}
try{ @<elq'2
oSavedFile.write(b,nStart,nLen); Fx2bwut.K
n = nLen; yPal<c
} 3qf Ym}d
catch(IOException e) r[*Vqcz
{ <_-hRbS
e.printStackTrace (); X<I+&Zi
} /#)/;
xsD($_
j-lfMEa$o
return n; %4gg@Z9
} ;'cN<x)%|
VcXq?f>\
()6wvu}
} >7QvK3S4%
=Lf,?"S
XzEc2)0'v
/* )84~ugs
**SiteInfoBean.java l`f/4vy
*/ N$U$5;r~`
package NetFox; md"!33 @
c"B{/;A
G6$kv2(k`@
public class SiteInfoBean { 'ZDp5pCC;
oY933i@l)P
v]B3m
private String sSiteURL; //Site's URL G?Q3/y(
private String sFilePath; //Saved File's Path @}}$zv6l,
private String sFileName; //Saved File's Name ;6>2"{NW
private int nSplitter; //Count of Splited Downloading File ]7Tkkw$
YTUZoW2
H}hiT/+$
public SiteInfoBean() `)T13Xv
{//nSplitter的缺省值为5 -;^j:L{
//default value of nSplitter is 5 )-a'{W/t
this("","","",5); &E.^jR~*
} ewctkI$,5
+JjW_Rl?=V
n[lJLm^(_C
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^\4h<M
{ {y=j?lD
sSiteURL= sURL; iKX-myCz
sFilePath = sPath; ]&lY%"U$i
sFileName = sName; _./Sk|C
this.nSplitter = nSpiltter; 1;Ou7T9w
wea-zN
b4[bL2J$h1
} H9YW
Y^$X*U/q%U
Y 0d<~*
public String getSSiteURL() t gI{`jS%
{ TFlet"ge=
return sSiteURL; j+$rj
} um!J]N^
Rh_np
O$_)G\\\m
public void setSSiteURL(String value) ]>=}*=
{ /|C*
sSiteURL = value; -zOdU}91Ao
} bk;?9%TW
H[,i{dD
f4 P8Oz
public String getSFilePath() I|gB@|_~
{ &$`P,i 1)
return sFilePath; F\KjEl0
} bDL,S?@
|H;F7Y_
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public void setSFilePath(String value) J^SdH&%Z
{ a_f~N1kq
sFilePath = value; cW@Zd5&0S
} +ElfZ4
hT`J1nNt
O}-jCW;K
public String getSFileName() zzTfYf)
{ e2s]{obf
return sFileName; HK,cJahq
} }wr{W:j
g{OwuAC_
GpY"fc%
public void setSFileName(String value) w$zu~/qV2
{ 3x{t(
sFileName = value; oM2l-[-
} Wh+{mvu#
I&}L*Z?`
SUCMb8
public int getNSplitter() n.!#P|
{ ZSjMH .Ij"
return nSplitter; yu!h<nfzA
} Ugu[|,
#5cEV'm;
Cl;oi}L
public void setNSplitter(int nCount) Rdvk ml@@
{ DFZkh^PFd
nSplitter = nCount; I`-8Air5f
} 5na~@-9p
} Uc7mOa}4
S?1AFI9{
`Q|*1
/* (eI5_`'VC
**Utility.java JjPKR?[>
*/ PF)jdcX
package NetFox; adCU61t
`^u>9v-+'
*6sl
public class Utility { K2M~-S3
qLn/2
+T|JK7
public Utility() [ey:e6,T9
{ ZZ2vvtlyG
`Nz/Oh7
4r>6G/b8*
} 8ja$g,
7X0Lq}G@
//线程睡眠 %HGD;_bhI
public static void sleep(int nSecond) U 9_9l7&r
{ (D#B_`;-
try{ Oft-w)cYz,
Thread.sleep(nSecond); -I*^-+>H
} H$=e -L`@
catch(Exception e) QLXN*c
{ Vq2y4D?
e.printStackTrace (); HG^B#yX
} .{ocV#{s
} jF ^~p9z
msP{l^%0
//日志 rID#`:Hl-|
public static void log(String sMsg) EN$2,qf
{ K-bD<X
System.err.println(sMsg); *W.C7=
} <;vbsksZeH
f,h J~
h].<t&
public static void log(int sMsg) "$#xK|t
{ ;YA(|h<
System.err.println(sMsg); |SoCRjuCPM
} }YB*]<]
} :o|\"3
\w/yF4,3<w
`IP/d
/* +ln9c
**TestMethod.java +]*zlE\N`
*/ ozmrw\_}[
package NetFox; UJD 0K]s
(U&tt]|
Li!Vx1p;u.
public class TestMethod { )m`<H>[Eb=
Rn}l6kbM
gp5_Z-me
public TestMethod() *,e:]!*
{ ///xx/weblogic60b2_win.exe ]JCvyz H
try{ -=%@L&y1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KC/=TSSXd.
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -m)X]]~C
SiteFileFetch fileFetch = new SiteFileFetch(bean); pOGeruu?
fileFetch.start(); 5Sm}nH
} GR&z,
catch(Exception e){e.printStackTrace ();} .:@Ykdm4I
fKeT,U`W
'C`U"I
} _7H7 dV
?{/4b:ua
G/b^|;41
public static void main(String[] args) wG~`[>y (
{ 3vuivU.3
new TestMethod(); "3Uv]F
} !Fca~31R'
} FG%X~L<d,)
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