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)); ,qx;kJJ
} sHk,#EsKH
for(int i=0;i<nEndPos.length-1;i++) _K4Igq
{ )FNvtLZ
nEndPos = nStartPos[i+1]; 7O_@b$Q
} _I("k:E7
nEndPos[nEndPos.length-1] = nFileLength; h 0EpW5
} #HMJBQ4v#
} e|`QW|9 .
QY]^^f
U"1z"PcV
//启动子线程 N36<EHq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -Y*"!8
for(int i=0;i<nStartPos.length;i++) mkA1Sh{hX>
{ ])d_B\)Kck
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w]4=uL6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), a(+.rf;
nStartPos,nEndPos,i); TRQ@=.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &f}a`/{@
fileSplitterFetch.start(); =%p%+F@RlW
} a3&&7n
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]et4B+=i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <<43'N+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4LO U[D
nEndPos = " + nFileLength); C%s+o0b
// fileSplitterFetch[nPos.length-1].start(); -&PiD
.'zXO
o"O=Epg
//等待子线程结束 8PWx>}XPt
//int count = 0; K`=O!;
//是否结束while循环 &WSxg&YG)\
boolean breakWhile = false; f0uzoeL<%
hJqLH?Ri
@a AR99M
while(!bStop) `0l)\
{ Dc,h(2
write_nPos(); ;Z\1PwT
Utility.sleep(500); 111s%
breakWhile = true; s "KPTV
U@W3x@
8|>$M
for(int i=0;i<nStartPos.length;i++) _j$"fg
{ P\;L#2n
if(!fileSplitterFetch.bDownOver) ^/|agQ7D2
{ gy|L!_1Z8
breakWhile = false; }T@^wY_Ow
break; 1Sk=;Bic
} ~F?vf@k
} "O{_LOJ
if(breakWhile) _[zZm*
break; =x9SvIm/tH
dP>~ExYtm
gyqM&5b
//count++; VR86ok
//if(count>4) 9FB[`}
// siteStop(); ;x 9_
} \8Mn[G9TL
J~=bW\^I
gbb2!q6p
System.err.println("文件下载结束！"); BCDmce`=l
} j]-0m4QF
catch(Exception e){e.printStackTrace ();} v'R{lXE
} _a;E>
^*CvKCS
3AKT>Wy =
//获得文件长度 }6;K+INT
public long getFileSize() v"nN[_T
{ N?xZ]?T
int nFileLength = -1; 6f"jl
try{ HGuU6@~hu
URL url = new URL(siteInfoBean.getSSiteURL()); 4o+SSS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _?j66-( Q
httpConnection.setRequestProperty("User-Agent","NetFox"); "I[a]T}/
KpHt(>NR
G.2\Sw
int responseCode=httpConnection.getResponseCode(); rF9|xgFK
if(responseCode>=400) `pMI@"m
{ B3x4sKs
processErrorCode(responseCode); gYeKeW3)
return -2; //-2 represent access is error #@ClhpLD
} ?]*WVjskE
F52%og~N
w}8 ,ICL
String sHeader; icO$9c
fQW1&lFT
6Zr_W#SE
for(int i=1;;i++) [HRry2#s
{ 0ge"ISK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :;Lt~:0b~
//Utility.log(in.readLine()); JD`IPQb~E
sHeader=httpConnection.getHeaderFieldKey(i); xq6 eu 9
if(sHeader!=null) 0bG[pp$[
{ (p19"p
if(sHeader.equals("Content-Length")) 6?;U[eV
{ rJjNoY
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); lN(|EI
break; 1c5+XCr
} 2 m"2>gX
} *5|;eN
else 'E\/H17
break; fL^$G;_?3
} {l E\y9
} L3/SIoqd
catch(IOException e){e.printStackTrace ();} ]\~s83?X
catch(Exception e){e.printStackTrace ();} 9"W3t]
M]Kxg;
~U;M1>
Utility.log(nFileLength); f|v5itO2
T!f+H?6
*VUD!`F
return nFileLength; D(;jv="/
} mNII-XG
1Yk!R9.
w@![rH6~F
//保存下载信息（文件指针位置） >='y+68
private void write_nPos() MyZ5~jnr\
{ ;L*Ku'6Mt
try{ `{oFdvL~)
output = new DataOutputStream(new FileOutputStream(tmpFile)); )%+7"7.
output.writeInt(nStartPos.length); e,?qwZK:y
for(int i=0;i<nStartPos.length;i++) +vr|J:
{ +=Y[RCXT
// output.writeLong(nPos); r!N> FE
output.writeLong(fileSplitterFetch.nStartPos); "Wb>y*S
output.writeLong(fileSplitterFetch.nEndPos); E%b*MU
} *Cj<Vy
output.close(); Hhzi(<e^
} ;hgRMkmz4<
catch(IOException e){e.printStackTrace ();} ` t6|09e
catch(Exception e){e.printStackTrace ();} I^GZ9@UE
} @$7'{*
_'mK=`>u
oypF0?!m
//读取保存的下载信息（文件指针位置） Z?f-_NHg
private void read_nPos() V[;^{,;
{ "$I8EW/1
try{ )p`zN=t
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J1u&Ga
int nCount = input.readInt(); Z#t}yC%^d
nStartPos = new long[nCount]; yog(
nEndPos = new long[nCount]; a7>^^?|
for(int i=0;i<nStartPos.length;i++) PJ))p6 9
{ Z]SUr`Z
nStartPos = input.readLong(); X|'[\v2ld
nEndPos = input.readLong(); wZg~k\_lF
} ROr|n]aJj
input.close(); X/f?=U
} O~OM.:al&
catch(IOException e){e.printStackTrace ();} S*NeS#!v
catch(Exception e){e.printStackTrace ();} L2Fi/UWM
} 4*&2D-8<K
z7s}-w,
r'<!wp@
private void processErrorCode(int nErrorCode) 8dLK5"_3
{ _Wtwh0[r*
System.err.println("Error Code : " + nErrorCode); 0TqIRUz "C
} `sLD>@m
f;%=S:3
BC)1FxsGf
//停止文件下载 G.:QA}FE'
public void siteStop() `PtfPt<{
{ w\1K.j=>|N
bStop = true; HP,{/ $i:
for(int i=0;i<nStartPos.length;i++) sdBB(
fileSplitterFetch.splitterStop(); 2-%9k)KH
KjK-#F,@
48)D%867.;
} avY<~-44B
} +' SG$<Xv
//负责部分文件的抓取 k!V@Q!>,
**FileSplitterFetch.java 07G'"=
*/ X`A+/{ H
package NetFox; l^2m7 7)
6eQa@[.Q
x~E\zw
import java.io.*; ub]s>aqy
import java.net.*; y=2nV
z:;yx
hm0MO,i"
public class FileSplitterFetch extends Thread { Y+DVwz$
Mu@(^zW
H`4KhdqR
String sURL; //File URL K?Jo"oy7
long nStartPos; //File Snippet Start Position GO3KKuQ=
long nEndPos; //File Snippet End Position Uka(Vr:
int nThreadID; //Thread's ID 0lU pil
boolean bDownOver = false; //Downing is over ~!P&LZ
boolean bStop = false; //Stop identical C,B{7s0-
FileAccessI fileAccessI = null; //File Access interface deOk>v&U
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-d[Gy- J
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6$t+Q~2G!
{ X2`n&JE
this.sURL = sURL; H#3Ma1z
this.nStartPos = nStart; PY#_$ C
this.nEndPos = nEnd; lL,0IfC,
nThreadID = id; sj&1I.@,>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #&Rx?V
} P"|-)d
h>A~yDT[
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public void run() >$7{H]
{ @xr}(.
while(nStartPos < nEndPos && !bStop) NCVhWD21|
{ C_&ZQlgQ
19i=kdH
1aezlDc*
try{ or(P?Ro
URL url = new URL(sURL); t\O#5mo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @%8$k[
httpConnection.setRequestProperty("User-Agent","NetFox"); nq\~`vH|Gd
String sProperty = "bytes="+nStartPos+"-"; cA~bH 6
httpConnection.setRequestProperty("RANGE",sProperty); jpZ 7p;
Utility.log(sProperty); *JO%.QNg
Wu)An
91UC>]}H
InputStream input = httpConnection.getInputStream(); _pkmHj(
//logResponseHead(httpConnection); lr=quWDY
]'<"qY
|Ew&.fgz
byte[] b = new byte[1024]; - H`,`#{
int nRead; M&KJZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) OG^#e+
{ :/6u*HwZh
nStartPos += fileAccessI.write(b,0,nRead); @Py?.H
//if(nThreadID == 1) VP^{-mDph
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HBZtg
} )Ut9k
V=E5pB`Pr
Ci?RuZ"
Utility.log("Thread " + nThreadID + " is over!"); AIw~@*T
bDownOver = true; :`S\p[5
//nPos = fileAccessI.write (b,0,nRead); #(-?i\i
} o),@I#fM
catch(Exception e){e.printStackTrace ();} EV_u8?va
} vAtR\Vh
} ]:Pkh./
eY_BECJ+OO
w +HKvOs5c
//打印回应的头信息 /U="~{*-R
public void logResponseHead(HttpURLConnection con) {<Xl57w-Q
{ ygxaT"3"=
for(int i=1;;i++) iThf\
{ wvH*<,8Vq
String header=con.getHeaderFieldKey(i); x";4)u=
if(header!=null) !X1 KOG
//responseHeaders.put(header,httpConnection.getHeaderField(header)); FZN}T{<
Utility.log(header+" : "+con.getHeaderField(header)); Hqb-)8 ~
else NYPjN9L
break; wdRk+
} ZSn6JV'g
} VW:Voc
Hm_&``='
Pk^V6-
public void splitterStop() #^w8Y'{?
{ 1t7T\~+F
bStop = true; WDh*8!)
} Z )X(
6t4{aa!L|9
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} !~]'&9
(!T\[6
#3YYE5cB
/* SKVQ !^o
**FileAccess.java z*WQ=l2
*//文件访问(定位，写) <#lNi.?.
package NetFox; xfA@GYCfT
import java.io.*; Cp#}x1{
FZfhiIf
||#+ ^p7G
public class FileAccessI implements Serializable{ NZuylQ)0
RYM[{]4b5F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {QT:1U\.
RandomAccessFile oSavedFile; \m+;^_;5GW
long nPos; `%=!_|
+\Je B/F
|L6 +e*
public FileAccessI() throws IOException lv&y<d;
{ 3_Mynop
this("",0); S,#UA%V"
} {Yv5Z.L&(
|@dY[VK>
l6-%)6u>
public FileAccessI(String sName,long nPos) throws IOException /?:q9Wy
{ OZno 3Hn
oSavedFile = new RandomAccessFile(sName,"rw"); <#e!kWGR?
this.nPos = nPos; -aIB_
oSavedFile.seek(nPos); CPu~^ik
} 8LlWXeD9
m"~),QwF9
K[9{]$(Z
public synchronized int write(byte[] b,int nStart,int nLen) 9S{0vc/2@
{ g#[,4o;
int n = -1; b IZi3GmRF
try{ \PK}4<x}
oSavedFile.write(b,nStart,nLen); ,/..f!bp
n = nLen; f/g-b]0
} s@|TQ9e |j
catch(IOException e) incUa;
{ 3mXRLx=0>
e.printStackTrace (); >('Z9<|r:
} "@@Z{
7R>Pk9J
F vHd`
return n; /@]@Tz@'
} )5ISkbsxD
Yx<wYzD
KgEfhO$W
} xu*dPG)v
mjbV^^>
SgY\h{{sP
/* JAI;7
**SiteInfoBean.java s%t =*+L\
*/ Z;J{&OJ3qM
package NetFox; \m1jV>q
<k-hRs2d
f}+8m .g2
public class SiteInfoBean { [^A>hs*
K_LwYO3
.l~g`._
private String sSiteURL; //Site's URL $Z4IPs
private String sFilePath; //Saved File's Path s@5r}6?M
private String sFileName; //Saved File's Name C/A~r
private int nSplitter; //Count of Splited Downloading File )` 90*
\UBQ:+3
f7j9'k
public SiteInfoBean() k^r-~q+NV#
{//nSplitter的缺省值为5 1IV R4:a
//default value of nSplitter is 5 ]LZ,>v
this("","","",5); 'Mm=<Bh
} $7bux1L
SDICN0X*
-O?&+xIK&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ajALca4
{ 6*=7ifS
sSiteURL= sURL; =CjN=FM
sFilePath = sPath; (Y$48@x
sFileName = sName; 8S7 YVsDz"
this.nSplitter = nSpiltter; Rz!!;<ye8
/V)4B4
cp<jwcc!
} #[ch?K
Blnc y
f/RDo4
public String getSSiteURL() }?XNA.Wz
{ @mId{w z
return sSiteURL; sn?YD'>k
} (w{C*iB
e&J_uG
S K7b]J>
public void setSSiteURL(String value) 3Mt Alc0xp
{ k?'<f
sSiteURL = value; MJ0UZxnl
} \cRe,(?O
_4#&!b6
KHJk}]K
public String getSFilePath() N_),'2
{ B!zqvShF
return sFilePath; zaoC
} N"q C-h
58H%#3Fy
.WT^L2l%
public void setSFilePath(String value) JOm6Zc
{ BbdJR]N/!h
sFilePath = value; K]Onb{QY
} ;5wr5H3
K{x FhdW
gaXKP1m^
public String getSFileName() CiSl0
{ b&1-tYV
return sFileName; 0x/3Xz
} >hbT'Or@
'fkaeFzOl
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public void setSFileName(String value) czv )D\*
{ 7yK1Q_XY>
sFileName = value; hfuGCD6F`
} C5^eD^[c
-d8||X[
@lnM%
public int getNSplitter() ]9}T)Df'
{ WgK|r~
return nSplitter; mC}!;`$8p
} 2og8VI
)"o+wSI1
\1p5$0z
public void setNSplitter(int nCount) :9Vd=M6,
{ VF<C#I
nSplitter = nCount; BLvI[b|3gn
} >`@yh-'r
} r 7mg>3
M"t=0[0DM:
%VCfcM}5I
/* !dW77kLTg
**Utility.java U8b1 sz
*/ pM i w9}
package NetFox; 8uO@S*)0
M5Twulz/w
{vJ)!'Eh
public class Utility { iWN-X (
l?/.uNw
`=0J:
public Utility() r_kw "9
{ z]YP
IHg)xZ
B~u_zZE
} f~.w2Cna
4#qjRmt
//线程睡眠 ClHaR
public static void sleep(int nSecond) IFX|"3[$
{ ?]=fC{Rh
try{ Iy}r'#N
Thread.sleep(nSecond); &E{5k{Y
} UEq;}4Bo
catch(Exception e) 8O]U&A@
{ J9LS6~ 7
e.printStackTrace (); 5g-apod
} :8_`T$8i4
} LaZF=<w(
9rb/hkX&
//日志 T$]2U>=<J
public static void log(String sMsg) }eX_p6bBw
{ ?;,Al`/^
System.err.println(sMsg); |<.b:e\4
} I`%=&l[v_5
$p4aNC
~^.&nph
public static void log(int sMsg) a{h(BI^~
{ Siw9_c
System.err.println(sMsg); We]X+>BlO
} @"s\eL,r
} s\&_Kbw]c
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fBH&AO$Q
/* Et'C4od s
**TestMethod.java bIm$7a`T
*/ 04;y%~,}U/
package NetFox; GtO5,d_
F!>K8q
P:k(=CzZ@J
public class TestMethod { i&,U);T
x#0C+cU
IQ{Xj3;?y
public TestMethod() ke>\.|HT}
{ ///xx/weblogic60b2_win.exe ]@J}f}Mjo
try{ 8{+~3@T
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A2&&iL=j/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "tIf$z
SiteFileFetch fileFetch = new SiteFileFetch(bean); oz5o=gt7
fileFetch.start(); ~+7yi4(i
} d L%E0o
catch(Exception e){e.printStackTrace ();} [/uKo13
GIVs)~/Eq
W? UCo6<m
} <(p1 j0_Q
J-PzIFWd
_R(5?rG,
public static void main(String[] args) 'v|2}T*
{ =w A< F
new TestMethod(); J#V`W&\,6
} paBGJ~{=
} j|G-9E
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