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)); ,69547#o
} Q+QD,
for(int i=0;i<nEndPos.length-1;i++) @*UV|$~(Q
{ c"1Z,M;G
nEndPos = nStartPos[i+1]; x1E;dbOZ
} 0XqxW\8_l
nEndPos[nEndPos.length-1] = nFileLength; gMPp'^g]_
} YZtd IG
} M&Ln'BC
n:1Ijh 1
H ="I=}
//启动子线程 inK;n
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X2:23j<
for(int i=0;i<nStartPos.length;i++) WlGT&m&2
{ d 792#Dc
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O;}K7rSc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [U"/A1p
nStartPos,nEndPos,i); JB.U&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uq54+zC
fileSplitterFetch.start(); b8vZ^8tBV
} 7~k=t!gTY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t&EY$'c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); iY&I?o!Ch
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E8p,l>6(f
nEndPos = " + nFileLength); Mk+G(4p
// fileSplitterFetch[nPos.length-1].start(); ?gjx7TQ?
tp&|*M3
$P%cdJT0
//等待子线程结束 ~$"2,&
//int count = 0; P4/~_$e
//是否结束while循环 j},i=v
boolean breakWhile = false; l5KO_"hy
27$,D XD
d/~g3n>|
while(!bStop) u3tT=5.D
{ U)aftH *Pk
write_nPos(); iXvrZofE
Utility.sleep(500); (vchZn#
breakWhile = true; _)~VKA]""
?~yJ7~3TS<
K1]3zLnS
for(int i=0;i<nStartPos.length;i++) *-Vr=e<8
{ %yk_(3a
if(!fileSplitterFetch.bDownOver) _u~0t`f~
{ 've[Mx
breakWhile = false; 8~TKiR5
break; lNWP9?X
} b>k2@
} LGX+_"
if(breakWhile) !7MRHI/0C
break; WBm)Q#1:
,_,*I/o>B
(hQi {
//count++; d~{$,"!-f
//if(count>4) 1)zXv
// siteStop(); =_ b/g
} j|!t3}((
d2-oy5cEB
lmL$0{Yr
System.err.println("文件下载结束！"); W}MN-0
} ?A*!rW:l;
catch(Exception e){e.printStackTrace ();} G'(rjH>q
} ',LC!^:~Nw
?#z<<FR
hCd? Kti
//获得文件长度 eR6vO5to
public long getFileSize() lCl5#L9
{ w&Gc#-B
int nFileLength = -1; }N$f=:iI
try{ Qf}.=(
URL url = new URL(siteInfoBean.getSSiteURL()); 8Gnf_lkI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uKvdL "
httpConnection.setRequestProperty("User-Agent","NetFox"); X;l/D},.
kLU-4W5t
woBx609Aak
int responseCode=httpConnection.getResponseCode(); ;DR5?N/a
if(responseCode>=400) Fkq^2o ]
{ _nxH;Za
processErrorCode(responseCode); +{I" e,Nk
return -2; //-2 represent access is error zR]!g|;f
} aW{5m@p{"
< *;GJ{
jvL!pEC!
String sHeader; %b4tyX:N0
`ZI-1&Y3
a_?b<
for(int i=1;;i++) .5}Gt>4XM
{ |g!d[ct]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); N2duhI6
//Utility.log(in.readLine()); V %D1Q}X
sHeader=httpConnection.getHeaderFieldKey(i); 32%Fdz1S
if(sHeader!=null) *h3iAcM8
{ ?h%Jb^#9
if(sHeader.equals("Content-Length")) ctjQBWE
{ &vn2u bauS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $uyx
break; '=#fELMW
} >8=lX`9f{
} 0.w7S6v|&
else 9:-7.^`P
break; }f?[m&<
} /sT?p=[.
} ctLNzJes%
catch(IOException e){e.printStackTrace ();} 2{vAs
catch(Exception e){e.printStackTrace ();} [Z#Sj=z
"*F`,I3
~QxW^DGa7]
Utility.log(nFileLength); [w|Klq5
_6ck@
,$>l[G;Bm
return nFileLength; LCtVM70
} '@Rk#=85Z
&r4|WM/ec
3,6f}:CG
//保存下载信息（文件指针位置） ::$W .!Uv
private void write_nPos() ~?HK,`0h>
{ m;MJ{"@A'
try{ [YHtBM:y
output = new DataOutputStream(new FileOutputStream(tmpFile)); (=Kv1 HaD
output.writeInt(nStartPos.length); qxu3y+po]
for(int i=0;i<nStartPos.length;i++) \U>&W
{ 3]mprX'
// output.writeLong(nPos); T]-MrnO
output.writeLong(fileSplitterFetch.nStartPos); [xr^t1
output.writeLong(fileSplitterFetch.nEndPos); L/C~l3
} LR>s2zu-
output.close(); !U m9ceK
} vIOGDI>
catch(IOException e){e.printStackTrace ();} K.Y`/<
catch(Exception e){e.printStackTrace ();} G:tY1'5
} P~=yTW
dgoAaS2M
OoH-E.lp
//读取保存的下载信息（文件指针位置） W.jXO"pN
private void read_nPos() .O5V;&,
{ Mh5> hD
try{ Q[rZ1z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H)7v$A,5%
int nCount = input.readInt(); ID,_0b
nStartPos = new long[nCount]; 9,`i[Dzp
nEndPos = new long[nCount]; rVoV@,P
for(int i=0;i<nStartPos.length;i++) P@vUQ
{ L-D4>+
nStartPos = input.readLong(); /3~L#jS
nEndPos = input.readLong(); 2[qfF6FHA
} WK(X/!1/k
input.close(); UgS`{&b36
} -8Mb~Hfl0
catch(IOException e){e.printStackTrace ();} Ue >]uZ|
catch(Exception e){e.printStackTrace ();} rpm\!O
} x0(bM g>7
2*z~'i
uMZ~[Sz
private void processErrorCode(int nErrorCode) <%S)6cw(3
{ 3J &Ros
System.err.println("Error Code : " + nErrorCode); fPUr O
} VYkh@j
89(qU
pQ:^ ziwa3
//停止文件下载 6` TwP\!$/
public void siteStop() Z}uY%]
{ )-Hs]D:
bStop = true; "}*D,[C5e
for(int i=0;i<nStartPos.length;i++) |;wc8;
fileSplitterFetch.splitterStop(); gI;"PkN
)c' 45bD
\\KjiT'
} ^?+[yvq
} P{6$".kIY
//负责部分文件的抓取 jL"V0M]c
**FileSplitterFetch.java '!7>*<
*/ `M6"=)twu
package NetFox; >aO.a[AM
:QGo -,6-
tSJ#
import java.io.*; yT@Aj;X0v
import java.net.*; h' !C
@`4T6eL5
aM;SE9/U
public class FileSplitterFetch extends Thread { Y_:jc{?
|di(hY|
S=!WFKcJR
String sURL; //File URL ?`Yu~a{
long nStartPos; //File Snippet Start Position .k]`z>uv
long nEndPos; //File Snippet End Position ?I[8rzBWU
int nThreadID; //Thread's ID lTMY|{9
boolean bDownOver = false; //Downing is over s"`~Xnf
boolean bStop = false; //Stop identical v7 *L3Ol
FileAccessI fileAccessI = null; //File Access interface nXLz<wE
j}ob7O&U'w
Mu[lk=jC
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #:gl+
{ 2MRd
this.sURL = sURL; OVi<d
this.nStartPos = nStart; fc*>ky.v
this.nEndPos = nEnd; 1#,4P1"
nThreadID = id; jL\j$'KC
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9,INyEyAL
} E.Xp\Dm71
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$kTm"I
public void run() x:MwM?
{ s"=TM$Vb
while(nStartPos < nEndPos && !bStop) SZ9Oz-?
{ >^jBE''
*zrGrk:l
X+XDfEt:Q
try{ ]|CcQ1#|H
URL url = new URL(sURL); l&+O*=#Hh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A[+)PkR
httpConnection.setRequestProperty("User-Agent","NetFox"); *HR pbe2
String sProperty = "bytes="+nStartPos+"-"; ?K[Y"*y2
httpConnection.setRequestProperty("RANGE",sProperty); j9>[^t3U
Utility.log(sProperty); Unb2D4&'
z1Ieva]
<!Cjq,Sk7
InputStream input = httpConnection.getInputStream(); h$'6."I
//logResponseHead(httpConnection); Ra|P5
l!x+K&
_HHvL=
byte[] b = new byte[1024]; #kM|!U=
int nRead; 6T$=(I <4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,yltt+e
{ AyO%,6p[
nStartPos += fileAccessI.write(b,0,nRead); f-|?He4O]
//if(nThreadID == 1) KBB)xez8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e^O:I
} Z|n|gxe
r&4Xf#QD6
+s}&'V^
Utility.log("Thread " + nThreadID + " is over!"); q!:dZES
bDownOver = true; $M)i]ekm
//nPos = fileAccessI.write (b,0,nRead); U=~?ca
} &6vaLx
catch(Exception e){e.printStackTrace ();} [WR"#y
} toPbFU'
} 7?whxi Qs
-4Hb]#*2
,6{z
//打印回应的头信息 MWv@]P_0p!
public void logResponseHead(HttpURLConnection con) a -Pz<*
{ -13}]Gls7Q
for(int i=1;;i++) 9-T<gYl
{ >XgJo7u
String header=con.getHeaderFieldKey(i); Pb'(Y
if(header!=null) x;7l>uR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Qf( A
Utility.log(header+" : "+con.getHeaderField(header)); uM`i!7}
else jlj ge=#c2
break; 66pjWS {X
} Pjs=n7
} "KP]3EyPc
>;MJm
Q<V(#)*
public void splitterStop() 61H_o7XXk
{ l%EvXdZuOy
bStop = true; AaYH(2m-
} !ddyJJ^a
Q[#}Oh6$
N4ZV+ |
} ({j8|{)+
?2&= +QaT
3Tu]-.
/* GmR3 a
**FileAccess.java {jO+N+Ez9
*//文件访问(定位，写) Np+PUu>
package NetFox; $$m0mK
import java.io.*; P5?VrZy
_ARG "
>O\+9T@
public class FileAccessI implements Serializable{ 5=C?,1F$A
!Sn|!:N4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?{ExBZNa
RandomAccessFile oSavedFile; CO`)XB6W
long nPos; )7*'r@
cK1^jH<|
$~6MR_Yq
public FileAccessI() throws IOException 6HK1?
{ )=Z;H"_
this("",0); s0' haU
} 32 i6j
7{}E{/
7_2D4CI
public FileAccessI(String sName,long nPos) throws IOException sg7h&<Xx
{ CnB[ImMs(A
oSavedFile = new RandomAccessFile(sName,"rw"); h}@wPP{
this.nPos = nPos; YjDQ`f/
oSavedFile.seek(nPos); ,7j8+p|},
} G~5pMyOR
|2l-s 1|y
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public synchronized int write(byte[] b,int nStart,int nLen) INr1bAe$
{ teS>t!d
int n = -1; "/6#Z>y
try{ $Lj]NtO
oSavedFile.write(b,nStart,nLen); {C5:as
n = nLen; >"2jCR$/
} i-wRwl4aEF
catch(IOException e) !-}Q{<2@W
{ I9Ohz!RQ
e.printStackTrace (); IVh5SS
} /GGyM]k3
Cw(e7K7&
72Bc0Wg
return n; et+lL"&
} B9NUafK=
X6 BIZ
sR9$=91`
} !tTv$L>
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z]N#.utQ
/* U*a#{C7"
**SiteInfoBean.java {%3WHGr%L
*/ "yw{A%J
package NetFox; <)TIj6
qkhre3
s8,YQ5-
public class SiteInfoBean { o)5zvnu7
twr{jdY9
/^xv1F{
private String sSiteURL; //Site's URL ZFtR#r(~41
private String sFilePath; //Saved File's Path 4N,[Gs<7
private String sFileName; //Saved File's Name 8~O#@hB~3
private int nSplitter; //Count of Splited Downloading File I]eeV+U8W
x >ah,
{nmu(EP
public SiteInfoBean() V| Fo@
{//nSplitter的缺省值为5 c)#7T<>*'
//default value of nSplitter is 5 6c]4(%8
this("","","",5); @;eH~3P
} 6 EqN>.
3yRvs;nWS
B7uK:J:c*H
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]z'L1vQl7
{ :Ob4WU
sSiteURL= sURL; o?}dHTk7
sFilePath = sPath; t,%m-dU
sFileName = sName; %q|*}l
this.nSplitter = nSpiltter; "J,|),Yd
ouCh2Y/_
=Lkn
} MPUyu(-%{
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q,ie)`
public String getSSiteURL() *N$XQ{o
{ '|]}f}Go
return sSiteURL; 9mHCms
} /UunWZ u%
&C MBTY#u
qWW\d', .
public void setSSiteURL(String value) T2rwK2
{ `>\ ~y1
sSiteURL = value; +>C26Q
} Y[L,rc/j
|5(un#
o+hp#e
public String getSFilePath() !X7z y9
{ O83J[YuzjN
return sFilePath; K7C <}y
} I7Kgi3
0z \KI?kd
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public void setSFilePath(String value) uH$hMg
{ !PoyM[Z"f
sFilePath = value; ^ q ba<#e
} iWeUsS%zpV
5)f 'wVe
H%m^8yW1
public String getSFileName() X$==J St
{ {P?Ge
return sFileName; VJ-t#q"
} Po=:-Of:
,9G'1%z,
xytWE:=
public void setSFileName(String value) MX~h>v3_R4
{ \ &|xMw[
sFileName = value; qWK}
} }2LG9B%
fV4eGIR&
0>j0L8#^p
public int getNSplitter() pWzYC@_W
{ XC6|<pru
return nSplitter; I;jH'._k#
} br88b`L
H$?MPA-c
W:<2" &7
public void setNSplitter(int nCount) ,+BFpN'
{ *8qRdI9
nSplitter = nCount; RQ|K?^k v
} Vfd_nD^8oZ
} e?(4lD)d
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Wp = ]YO
/* Z5rL.a&
**Utility.java ^'N!k{x
*/ |7|'JTy
package NetFox; rk=w~IZJ3
=^M Q 4
b/.EA'/
public class Utility { =Cf@!wZ^
XU"G
Wx/PD=Sf&
public Utility() *9KT@"v
{ I@N/Y{y#
U{EcV%C2
l{rHXST|
} g NE"z
uUaDesz~=
//线程睡眠 ax _v+v %
public static void sleep(int nSecond) dn~k_J=p
{ D_F1<q
try{ # .&t'"u
Thread.sleep(nSecond); 9_*3xu<7i
} ~]%re9jGW
catch(Exception e) rr1,Ijh{D
{ Q.4+"JoG
e.printStackTrace (); {3os9r,
} $!'Vn)Z7
} G|&$/]~
%j0c|u
//日志 agoMsxI9
public static void log(String sMsg) F$v^S+Ch
{ cPL6(&7
System.err.println(sMsg); sFk{Tv@Yz
} CU\r I
\SmYxdU'>
T;kh+i
public static void log(int sMsg) Ktuv a3=>N
{ aQWg?,Ju6
System.err.println(sMsg); 5#_GuL%
} V+'zuX
} !Y^B{bh
bneP>Bd
A{{rNbCK
/* Z~ q="CA4
**TestMethod.java 0n{+_
*/ H5FWk
package NetFox; suX^"Io%!
o9D#d\G
!9C]Fs*`?
public class TestMethod { Ov:U3P?%
]C_$zbmi
w&^Dbme
public TestMethod() U&+lw=
{ ///xx/weblogic60b2_win.exe FGMYpapc~
try{ #s=\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d8jP@>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j}%C;;MPH
SiteFileFetch fileFetch = new SiteFileFetch(bean); c@O7,y:`I
fileFetch.start(); noWwX
} Em<J{`k6
catch(Exception e){e.printStackTrace ();} z[+pN:47
8 =3#S'n
dr=KoAIxy
} r)w]~)8
AIQ]lQ(
qy!pD R;
public static void main(String[] args) vdulrnGqL
{ !\Q/~p'jS
new TestMethod(); V+y:!t`
} uc;,JX!bN
} HX:^:pF}
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