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)); UC+7-y,
} le^_6|ek
for(int i=0;i<nEndPos.length-1;i++) x<*IF,o
{ aEEz4,x_
nEndPos = nStartPos[i+1]; uVq5fT`B
} k99gjL`
nEndPos[nEndPos.length-1] = nFileLength; b1+hr(kMRM
} -_EY$?4
} )`s;~_ZZ
>^H'ZYzw
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//启动子线程 Ck3QrfM
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =|gJb|?w
for(int i=0;i<nStartPos.length;i++) 3Zaq#uA
{ ])QO%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jV4hxuc$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), VM!-I8t
nStartPos,nEndPos,i); +Y5(hjE
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BA1MGh
fileSplitterFetch.start(); t(j_eq}J
} ,a9D~i 9R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xgtJl}L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); B%eDBu ")
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^Cc8F3os=
nEndPos = " + nFileLength); k_K,J6_)
// fileSplitterFetch[nPos.length-1].start(); e+F}9HR7
j(Fa=pi
Q3BLL`W~
//等待子线程结束 9QC"Od9H
//int count = 0; x5fgF;
//是否结束while循环 ~tg1N^]kV
boolean breakWhile = false; J})$
wuIsO;}/9
c_qcb7<~.
while(!bStop) -- i&"
{ 9raHSzK@d
write_nPos(); ;# R3k
Utility.sleep(500); VBbUl|X\
breakWhile = true; %="~\1y
u>,lf\Fgz
to!mz\F
for(int i=0;i<nStartPos.length;i++) e0v9uQ%F5
{ ;Na8_}
if(!fileSplitterFetch.bDownOver) nW$A^
{ S_T{L
breakWhile = false; &Rt+LN0qB0
break; } g3HoFC
} QmH/yy3.%
} d7W%zg\T
if(breakWhile) FX|0R#4vm
break; FylWbQU9
/'Quu)~
G}=`VYK
//count++; CdBthOPX)
//if(count>4) iO%Zd[
// siteStop(); VO.-.
} ``(}4a
0)A=+zSS1
Xzx[C_G
System.err.println("文件下载结束！"); wUZQB1$F
} NK+FQ^m[
catch(Exception e){e.printStackTrace ();} '^Pq(b~
} JdaFY+f:
ee&nU(pK
$xRo<,OV+
//获得文件长度 o5N]((9
public long getFileSize() 0M#N=%31
{ dr|| !{\
int nFileLength = -1; z3^RUoGU
try{ 7XUhJN3n
URL url = new URL(siteInfoBean.getSSiteURL()); eZ!yPdgy|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f![xn2T
httpConnection.setRequestProperty("User-Agent","NetFox"); y!7B,
ZhGh{D[,
Nl~Z,hT$*
int responseCode=httpConnection.getResponseCode(); 9USrgY6_
if(responseCode>=400) Rz.i/wg}
{ "t5 +*
processErrorCode(responseCode); W;fH&r)d@
return -2; //-2 represent access is error qxf+#
} ?*CRa$_I|
sTd}cP
5"1!p3`\D{
String sHeader; /yx=7<
Jq#[uX
8_"3Yb`f
for(int i=1;;i++) "NxOOLL
{ J*}VV9H
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ijvNmn1k
//Utility.log(in.readLine()); r@|R-Binz
sHeader=httpConnection.getHeaderFieldKey(i); T1lXYhAWS
if(sHeader!=null) ^D9 /
{ i'M^ez)u
if(sHeader.equals("Content-Length")) nHI(V-E2:H
{ `[X6#`<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rU; g0'4e
break; 8'3"uv
} k!Vn4?B"k
} &[NVP&9&U
else S#P+B*v
break; ^Lsc`<xC
} ~J%R-{U9
} a;56k
catch(IOException e){e.printStackTrace ();} uAp -$?
catch(Exception e){e.printStackTrace ();} x HY+q;
M{*kB2jr
&@=u+)^-{
Utility.log(nFileLength); TRSOO}
h^['rmd
'/Cg*o/
return nFileLength; (d54C(")
} k|^vCZ<(x
,`D/sNP,q
B`LD7]ew
//保存下载信息（文件指针位置） >-VWm A
private void write_nPos() CIIY|DI`l
{ Lqg]Fd
try{ kVWGDI$~
output = new DataOutputStream(new FileOutputStream(tmpFile)); 63.( j P1;
output.writeInt(nStartPos.length); gB>(xY>LrA
for(int i=0;i<nStartPos.length;i++) 3b<: :t
{ O-i4_YdVt
// output.writeLong(nPos); vB Sm=M
output.writeLong(fileSplitterFetch.nStartPos); _i-\mR_~
output.writeLong(fileSplitterFetch.nEndPos); k&OC&
} $RpFxi
output.close(); \^yXc*C
} D=2~37CzQ1
catch(IOException e){e.printStackTrace ();} <H<!ht%q3
catch(Exception e){e.printStackTrace ();} \.5F](:
} .H ,pO#{;
ex.+'m<g
&8Zeq3~
//读取保存的下载信息（文件指针位置） 3b#L17D3_
private void read_nPos() j0AwL7
{ 7`Qde!+C
try{ >+L7k^[,0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |Es0[cU
int nCount = input.readInt(); Ny[QT*nV
nStartPos = new long[nCount]; (viWY
nEndPos = new long[nCount]; =ntftSH
for(int i=0;i<nStartPos.length;i++) KCE=|*6::|
{ 5n:nZ_D
nStartPos = input.readLong(); !zU/Hq{wcK
nEndPos = input.readLong(); N A8 sN
} 0%/,>IR>r
input.close(); VXiui'/(
} wqcDAO(
catch(IOException e){e.printStackTrace ();} 6Ux[,]GK
catch(Exception e){e.printStackTrace ();} '[%jjUU
} ?qy*s3j'M
[@ILc*2O
3]N q@t
private void processErrorCode(int nErrorCode) wXz\NGW
{ Qy/uB$q{A
System.err.println("Error Code : " + nErrorCode); *E.LP1xP
} +.=1^+a
;;M"hI3@
]7*kWc2
//停止文件下载 ;3mL^
public void siteStop() >8%M*-=p
{ Ha?G=X
bStop = true; lHcA j{6
for(int i=0;i<nStartPos.length;i++) <&`:&7
fileSplitterFetch.splitterStop(); WXLK89ev\
xg?auje
}*h47t}
} kj-=xhJ{=
} Mw+v"l&mU
//负责部分文件的抓取 ,'=hjIel
**FileSplitterFetch.java 7q!?1 -?8R
*/ 0fA=_=A,
package NetFox; B& "RS
fSbS(a
'(tj[&aL
import java.io.*; @`6}`k
import java.net.*; .wP/ai>}
e#1.T
hzq5![/sV
public class FileSplitterFetch extends Thread { >:A<"wZ
as(;]
zOL;"/R
String sURL; //File URL ;uK";we
long nStartPos; //File Snippet Start Position *<7l!#
long nEndPos; //File Snippet End Position s"q=2i
int nThreadID; //Thread's ID d @m\f
boolean bDownOver = false; //Downing is over bf1)M>g,O
boolean bStop = false; //Stop identical a#$N%=j
FileAccessI fileAccessI = null; //File Access interface qIz}$%!A
^,`M0g\$
S#mK Pi+3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException f\ 'T_
{ C!5I?z&
this.sURL = sURL; &~'S)Nun
this.nStartPos = nStart; [z2eCH
this.nEndPos = nEnd; Xo\S9,s{
nThreadID = id; eSn$k:\W
fileAccessI = new FileAccessI(sName,nStartPos);//定位 h D.)M
} *,0+RASvq
nZxSMN0]
+mLD/gK`
public void run() 7k'gt/#up
{ &sdx`,
while(nStartPos < nEndPos && !bStop) 6Kp}_^|z
{ }3J=DCtS
J+|/-{g
modC6d%
try{ Z%OW5]q
URL url = new URL(sURL); 0p `")/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (-(QDRxK
httpConnection.setRequestProperty("User-Agent","NetFox"); T)~!mifX
String sProperty = "bytes="+nStartPos+"-"; -=a[J;'q
httpConnection.setRequestProperty("RANGE",sProperty); \E77SO,$
Utility.log(sProperty); 5B?i(2&#
Im+7<3Z
Yz\ N&0"
InputStream input = httpConnection.getInputStream(); X8Fzs!L`
//logResponseHead(httpConnection); BPewc9RxV
P$OUi!"
v%nP*i9
byte[] b = new byte[1024]; $''UlWK
int nRead; ?A&%Cwj
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) G|*G9nQ
{ 7&foEJ3q
nStartPos += fileAccessI.write(b,0,nRead); ~)?|J
//if(nThreadID == 1) R5ZIC4p
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N2Ssf$
} >Nh`rkR2[
*VDVC0R
)NIv "Q
Utility.log("Thread " + nThreadID + " is over!"); `XgFga)
bDownOver = true; B`1kGEx .
//nPos = fileAccessI.write (b,0,nRead); ?-,6<K1
} j^nu|
catch(Exception e){e.printStackTrace ();} \c%g M1
} 9@'4P
} hl]S'yr
!}t-j3bCs
V%51k{
//打印回应的头信息 r]T0+oQ>
public void logResponseHead(HttpURLConnection con) T,OS0;7O
{ ]]PE#DDg
for(int i=1;;i++) \z:<DsQ&
{ CN\=9Rvs
String header=con.getHeaderFieldKey(i); yb?|Eww_o
if(header!=null) l'uOORI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $8g42LR'
Utility.log(header+" : "+con.getHeaderField(header)); p9iu:MucD<
else V;;#/$oU:4
break; N}mh}
} w & P&7
} ]\dHU.i
t^U^Tr
AY88h$a
public void splitterStop() R6P\T\~E
{ BIj
bStop = true; c\K<sM{
} $>r5>6
:)4*^a/lC
U&W"Ea=R/
} $3\,h;y
YlKFw|=
Y.-S=Y
/* T5e^J"
**FileAccess.java q.T:0|
*//文件访问(定位，写) H,K`6HH
package NetFox; ?1w"IjUS
import java.io.*; ag;dc
FN\GE\H
;;Tq$#vd
public class FileAccessI implements Serializable{ -?fR|[\[U
t!qwxX*$T
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 IaasHo\
RandomAccessFile oSavedFile; 5g0_WpO
long nPos; S{:Cu}o
7 :U8 f:
t$I|E
public FileAccessI() throws IOException l"\uf(0K
{ U=m=1FYaG
this("",0); m&/=&S
} ~kb{K;
PeNF+5s/K
_ECB^s_
public FileAccessI(String sName,long nPos) throws IOException S>t>6&A
{ OZOb1D
oSavedFile = new RandomAccessFile(sName,"rw"); [r9d<Zi}{
this.nPos = nPos; nzuF]vo
oSavedFile.seek(nPos); xS+rHC
} eY}V9*.v
wS$46M<
u"FjwF?
public synchronized int write(byte[] b,int nStart,int nLen) "b%FmM
{ 0( //D;j
int n = -1; WeVi]n
try{ :Ss3ck*=
oSavedFile.write(b,nStart,nLen); n)RM+g
n = nLen; 3U;1D2"AE
} kUbnVF5'
catch(IOException e) CDCC1BG"
{ 2f..sNz
e.printStackTrace (); RxG^
} z<<Tk.65
Gru ALx7
u-.L^!k
return n; '[fZt#
} ~L'nzquF
f#OQ (WTJE
ZqK]jT6V/X
} %rcFT_
T4GW1NP
N`1r;%5
/* lRND
**SiteInfoBean.java r/PKrw sC
*/ *rf$>8~$n
package NetFox; aR)?a;}H
M[s\E4l:t
zH=hIVc
public class SiteInfoBean { Dl A Z"C
p+<}YDMb
K\^&+7&zVg
private String sSiteURL; //Site's URL t.U{Bu P
private String sFilePath; //Saved File's Path Pz`hX$
private String sFileName; //Saved File's Name \]8i}E1
private int nSplitter; //Count of Splited Downloading File /^4"Qv\@/
j@v-|
D9o*8h2$
public SiteInfoBean() Ub)M*Cq0(o
{//nSplitter的缺省值为5 aQ|hi F}
//default value of nSplitter is 5 8*Zvr&B,G
this("","","",5); 4bI*jEc\[
} M&[b.t*
F$yeF^\g
[Vp\$;\nT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Le&;g4%
{ , N 344y
sSiteURL= sURL; J"&y|;G
sFilePath = sPath; oEIqA
sFileName = sName; YiZx{5
this.nSplitter = nSpiltter; v<&v]!nF
sykFSPy`'
sN]Z #7
} [z+x"9l0!
>EIrw$V$
x'i0KF
public String getSSiteURL() #LWg"i
{ wPH+n-&e
return sSiteURL; <25ccE9^c
} &7Kb]Ti
g1V)$s7
<V S2]13
public void setSSiteURL(String value) !Uy>eji}
{ e1^l.>2d6
sSiteURL = value; |yv]Y/=
} c&e0OV\m
^Y 7U1I
,8VXA +'_
public String getSFilePath() yVYkuO
{ xJc.pvVPw
return sFilePath; [YE?OQ7#
} FL&dv
TQ-KkH}y
LyP`{_"CM
public void setSFilePath(String value) a}yR p
{ VDn:SGj5
sFilePath = value; )7AM3%z1?
} Efr3x{ j
4Py3I9
UkfA}b^@v
public String getSFileName() b1)\Zi
{ v,0<9!'v
return sFileName; 7d9Z/J@>
} /7vE>mSY
0WXVc
**HrWM%?8o
public void setSFileName(String value) E9R]sXf8
{ L*^ V5^-
sFileName = value; .vaJAvg
} 5!h<b3u>]
NWnWk
C P&o%Uc*
public int getNSplitter() )_Iz>)
{ {aIZFe}B
return nSplitter; dEET}s\
} R@$+t:}
k=|K|
r=\P!`{5
public void setNSplitter(int nCount) `oXg<tivU
{ t= *Jg/$
nSplitter = nCount; ;qb Dbg
} y/\ZAtnLo
} ;sQ20 B'
f1\7vEE,
_yJ|`g]U3
/* Ql8^]gbp+
**Utility.java %omu
*/ y#e ?iE@
package NetFox; !ew6 n I
,!H\^Vfl
#[(gIOrNn8
public class Utility { D-D#`
I4:rie\hjC
?FDJqJM
public Utility() 8})|^%@n
{ f}blB?e
6VFirLd
=h7[E./U1
} |?yE^$a
xD^wTtT
//线程睡眠 pJ6Jx(
public static void sleep(int nSecond) Rdj8*f
{ )r#,ML
try{ hpas'H>J
Thread.sleep(nSecond); O!,Ca1N
} l.uN$B
catch(Exception e) Z*Zc]hD
{ Bs@:rhDi
e.printStackTrace (); 8W@dtZ,d
} p9Z].5Pd"
} 9BO|1{
,3k@L\$.x
//日志 0}D-KvjyP
public static void log(String sMsg) 4uPH
{ Q-3r}jJe
System.err.println(sMsg); ajGcKyj8i
} IqXBz.p
Fr2kbQTg;
W7$s5G,
public static void log(int sMsg) y,V6h*x2
{ -EVs@:3]j
System.err.println(sMsg); VZTmzIk.Y
} X'xUwT|_+
} n_1jHJo
@wMQC\Z
@Jm.HST#S8
/* {x9j_/R
**TestMethod.java Xout:dn
*/ r:73uRk
package NetFox; 3Qk/ Ll
nPcxknl(pd
a^(2q{*
public class TestMethod { ^glX1 )
{N"*olx
7MoR9,(
public TestMethod() z>7=k`x`:
{ ///xx/weblogic60b2_win.exe 6-tiRk~
try{ %uj[`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~z&0qQ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); WX ,p`>n
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;eP_;N5+J
fileFetch.start(); p1klLX
} ^]i" H|(x
catch(Exception e){e.printStackTrace ();} @K7ebYr?
<o~t$TH
&{BBxv)y
} ?THa5%8f
>n1h^AW
We\KDU\n
public static void main(String[] args) #jOOsfH|k
{ dV)Y,Yx0${
new TestMethod(); \|blRm;
} WFRsSp2
} ~m!#FTc*
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