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)); d?9b6k?
} /Wx({N'h$
for(int i=0;i<nEndPos.length-1;i++) Kw/7X[|'G
{ BQOit.
nEndPos = nStartPos[i+1]; P{2ue`w[
} Z)Zc9SVC
nEndPos[nEndPos.length-1] = nFileLength; K}OY!|
} j=],n8_i
} i 6DcLE
_ Vo35kA
ru>c\X^|
//启动子线程 #Yd'Vve
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bE6:pGr
for(int i=0;i<nStartPos.length;i++) -zSkon2Y^
{ 'zUWO_(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l(B(gPvU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ab@1JAgs
nStartPos,nEndPos,i); VhfMj|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +[lv `tr
fileSplitterFetch.start(); uE;bNs'
} o<\uHr3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rFJPeK7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); DI)!x {"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", t ;-U
nEndPos = " + nFileLength); X<8
// fileSplitterFetch[nPos.length-1].start(); ';vLj1v
_U<r@
E3~Wyfd7
//等待子线程结束 >[qoNy;
//int count = 0; ?TLzOYJp
//是否结束while循环 lx H3a :gm
boolean breakWhile = false; [S:{$4&
^C|N
@dHQ}Ni
while(!bStop) ]Jum(1Bo
{ >"/Sa_w
write_nPos(); C25EIIdRb
Utility.sleep(500); vMHJgpd&j
breakWhile = true; LJ{P93aq`^
OMz_xm.UPi
7jzd I!
for(int i=0;i<nStartPos.length;i++) EyK F5TP0
{ Ia%S=xU{=
if(!fileSplitterFetch.bDownOver) "BvAiT{u
{ 3[UB3F4K
breakWhile = false; i2yE-sgF
break; p_:bt7 B
} `JZ`j7f
} 6|@\\\l
if(breakWhile) 1:j[p=Q&
break; U(~d^9/#
nvOJY6)$V
sVNM#,
//count++; I$Ra*r
//if(count>4) ?H0"*8C?Y
// siteStop(); 5bHS|<
} gY/p\kwsj
tYzpL
2l.qINyz
System.err.println("文件下载结束！"); IPa)+ ZQ
} qHf8z;lc
catch(Exception e){e.printStackTrace ();} y7@q]~%
} |qq7vx
Js0hlWu
"74Rn"d5
//获得文件长度 Kd|@
public long getFileSize() @ rG=>??k
{ @@pI>~#zh
int nFileLength = -1; &~&nJr
try{ ?(2^lH~6h
URL url = new URL(siteInfoBean.getSSiteURL()); QG8X{'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T@?uA*J
httpConnection.setRequestProperty("User-Agent","NetFox"); _@_w6Rh
'g#EBy
H"vy[/UcR
int responseCode=httpConnection.getResponseCode(); 6_zyPh
if(responseCode>=400) YkJnZ_k/P
{ %1UdG6&J_
processErrorCode(responseCode); RKtU@MX49
return -2; //-2 represent access is error %kXg|9Bx!
} Y| 2Gj(*8
5m\T~[`%
nm{J
String sHeader; ;+NU;f/WM
fZNWJo# `.
NzAMX+L
for(int i=1;;i++) VPI;{0kh
{ 0~GtK8^B
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Sft+Gb6
//Utility.log(in.readLine()); rzO5 3\
sHeader=httpConnection.getHeaderFieldKey(i); V'm4DR#M
if(sHeader!=null) }0f"SWO>
{ s+7#TdhA
if(sHeader.equals("Content-Length")) u~7 ,v
{ F\BD7W
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); p`mNy o'
break; tO8<N'TD
} /5&'U!:+
} SMIr@*R
else u0?,CQPL
break; t(Sjo8, b
} :J~sz)n4
} D)){"Q!b
catch(IOException e){e.printStackTrace ();} uNXKUJ V0
catch(Exception e){e.printStackTrace ();} R\ZyS )~l
_I A{I
e)):U
Utility.log(nFileLength); d7i 0'R
W,-fnJk
kr{eC/Q"
return nFileLength; J{qpGRQNa
} m)oGeD( !
G~FAChI8![
sUTfY|<7|
//保存下载信息（文件指针位置） *-lw2M9V
private void write_nPos() "&{sE RYY
{ am(jmf::
try{ ]<g`rR7}
output = new DataOutputStream(new FileOutputStream(tmpFile)); t/Y)%N
output.writeInt(nStartPos.length); Ow f:Kife
for(int i=0;i<nStartPos.length;i++) (sN;B)
{ 'rSP@
// output.writeLong(nPos); JV_V2L1Ut
output.writeLong(fileSplitterFetch.nStartPos); c@<vFoq
output.writeLong(fileSplitterFetch.nEndPos); _X"G(
} Y2 QX9RN
output.close(); 04}" n
} )D>= \Me
catch(IOException e){e.printStackTrace ();} *wNO3tP't
catch(Exception e){e.printStackTrace ();} Di>B:=
} /+g)J0u
Lcow2 SbH
C'oNGOEd
//读取保存的下载信息（文件指针位置） ,3p$Z
private void read_nPos() o@j)clf
{ ;:#g\|(<+
try{ % >}{SS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \95O
int nCount = input.readInt(); Qs1e0LwA9
nStartPos = new long[nCount]; lq*{2M{[
nEndPos = new long[nCount]; EI!e0V1!
for(int i=0;i<nStartPos.length;i++) f.Feo
{ 8-uRn38
nStartPos = input.readLong(); Y>i5ubR~
nEndPos = input.readLong(); b@?pofZ`k
} vzPuk|q3
input.close(); z(JDLd
} eA'1
catch(IOException e){e.printStackTrace ();} p"k[ac{
catch(Exception e){e.printStackTrace ();} `S+B-I0
} @teNT"
G.y~*5?#
.!Qo+(
private void processErrorCode(int nErrorCode) +#=l{_Z,ZJ
{ $Q'S8TU
System.err.println("Error Code : " + nErrorCode); p|,3X*-ynx
} N&K`bmtD
w$%1j+%&
TF7~eyLg
//停止文件下载 REc+@;B
public void siteStop() R}J}Qb
{ %IhUQ6
bStop = true; *!-J"h
for(int i=0;i<nStartPos.length;i++) 9W+RUh^W
fileSplitterFetch.splitterStop(); KE*8Y4#9
7,:$, bL
pxgVYr.
} j$mCU?
} lOJ3_8
//负责部分文件的抓取 f'28s*n
**FileSplitterFetch.java QxS=W2iN
*/ Qqn9nO9
package NetFox; q{E44 eQ7F
Pt^SlX^MM
zEN3Nn.8
import java.io.*; w(-h!d51+
import java.net.*; 1Bhd-
q[Ed6FM$~
c3]X#Qa#m$
public class FileSplitterFetch extends Thread { 1p }:K`#{
[t}\8^y
\Uh$%#}.
String sURL; //File URL ##_Jz5P
long nStartPos; //File Snippet Start Position gtVnn]Jh
long nEndPos; //File Snippet End Position RwyRPc_
int nThreadID; //Thread's ID x-%4-)
boolean bDownOver = false; //Downing is over | g[iK1
boolean bStop = false; //Stop identical gSn9L)k(O
FileAccessI fileAccessI = null; //File Access interface U,e'vS{
lwj,8
M*n@djL$\~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _&xi})E^O]
{ lU&[){
this.sURL = sURL; KYN{Dh]-}
this.nStartPos = nStart; r< ~pSj
this.nEndPos = nEnd; '7;b+Vbl#
nThreadID = id; ZA{T0:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <]e0TU?bk
} 3d81]!n
6xq/
jSc!"Trl]
public void run() bxR6@
{ BfOQ/k))
while(nStartPos < nEndPos && !bStop) H)VzPe#{
{ 7 S6@[-E
&upM,Jsr*
c4i%9E+Af
try{ 6! .nj3$*
URL url = new URL(sURL); >A_:qyGk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1 |T{RY5
httpConnection.setRequestProperty("User-Agent","NetFox"); {Z!x]}{M
String sProperty = "bytes="+nStartPos+"-"; uzgQ_
httpConnection.setRequestProperty("RANGE",sProperty); M|DVFC
Utility.log(sProperty); ;FfDi*S7
3 jRI@
K0xka[x=(
InputStream input = httpConnection.getInputStream(); YggeKN
//logResponseHead(httpConnection); &'KJh+jJ
4M,Q{G|e
Z(c3GmY
byte[] b = new byte[1024]; -{O>'9'1A
int nRead; JVxGS{Z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) lo< t5~GQ
{ }fT5(+ Wo
nStartPos += fileAccessI.write(b,0,nRead); :plN<8
//if(nThreadID == 1) 4Fs5@@>X
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RM|2PG1m
} l>){cI/D#
'^10sf`"
YDxEWK<
Utility.log("Thread " + nThreadID + " is over!"); 1r?hRJ:'
bDownOver = true; 0+dc
//nPos = fileAccessI.write (b,0,nRead); J<;@RK,c_
} d":GsI?3
catch(Exception e){e.printStackTrace ();} U_[<,JE
} 1=U NA :t<
} 68 \73L=
hI>vz"J
DElrY)3O.
//打印回应的头信息 Q/zlU@
public void logResponseHead(HttpURLConnection con) ;eY.4/*R
{ !> 2kH
for(int i=1;;i++) Wb{0UkApJ
{ hb="J349
String header=con.getHeaderFieldKey(i); =`pH2SJT
if(header!=null) z&KrG
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3LW_qX
Utility.log(header+" : "+con.getHeaderField(header)); 0aM&+j\q}
else ^Iy'G44
break; 6 @A'N(I=O
} Mv?$zV"`#
} wSd|-e
A}3dx!?7j
l' mdj!{&
public void splitterStop() `p'682xI
{ @ Cd#\D|
bStop = true; }5]2tH${
} KBOp}MEz
!*G%vOa
N5d)&a 7?
} gzd<D}2F~
QCAoL.v
aDZ,9}
/* C116c"
**FileAccess.java fHd|tl
*//文件访问(定位，写) VSjt|F)t
package NetFox; (|9t+KP
import java.io.*; G$mAyK:
N3(.7mxo
J~.`
public class FileAccessI implements Serializable{ v2l*n
F87/p
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 K;Fs5|gFU
RandomAccessFile oSavedFile; lW|`8ykp
long nPos; W+Q^u7K
SxI-pH'
Ms 3Sri
public FileAccessI() throws IOException u*=8s5Q[
{ 572{DC&T
this("",0); [nASMKK0
} mgE r+
).3riR
^_gH}~l+U
public FileAccessI(String sName,long nPos) throws IOException e);`hNLih
{ Z^!% b
oSavedFile = new RandomAccessFile(sName,"rw"); 6o d^+>U
this.nPos = nPos; Y*/e;mG.
oSavedFile.seek(nPos); LU $=j
} %jJ|4\
$a'}7Q_
RJ1@a
public synchronized int write(byte[] b,int nStart,int nLen) Dbu>rESz
{ SA?lDRF
int n = -1; PH$C."Vv
try{ U'aJCM
oSavedFile.write(b,nStart,nLen); VVJIJ9L&C
n = nLen; 9? y&/D5O
} cq0-Dd9^&
catch(IOException e) ryNe=9p
{ 5=&ME(fmV
e.printStackTrace (); c!ieN9^+
} +"1fr
.XT]\'vW
-v! ;
return n; YeS5%?Fk
} qV0GpVJZU?
G=/^]E
Ggry,3X3
} =P%?{7
;pj,U!{%s\
-}u1ZEND
/* " GY3sam
**SiteInfoBean.java !bs5w_@
*/ mw&'@M_(7
package NetFox; {T-=&%||
x[=,$;o+
3Cgv($xl&
public class SiteInfoBean { "5204I
a<J<Oc!
iPdS>ee
private String sSiteURL; //Site's URL lAR1gHhJ
private String sFilePath; //Saved File's Path Kr?<7vMT5
private String sFileName; //Saved File's Name ~BiLzT1,
private int nSplitter; //Count of Splited Downloading File Gz52^O:
U+R9bn
vnWt8?)]^
public SiteInfoBean() (8baa.ge
{//nSplitter的缺省值为5 EU7nS3K)O~
//default value of nSplitter is 5 RN&6z"|jR
this("","","",5); EM(%|#
} /dO*t4$@?
%l?*w~x
+%H=+fJ2}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) x_t$*
{ ^WF_IH&
sSiteURL= sURL; aJ@lT&.
sFilePath = sPath; fr'DV/T
sFileName = sName; $xCJ5M4
this.nSplitter = nSpiltter; CaV@<T
+p[O|[z
+/ {lz8^,
} <0;G4fE7[H
d3\KUR^
BiDyr
public String getSSiteURL() |ZC'a!
{ T% GR{mp
return sSiteURL; <Sr:pm
} B}nT>Ub
&dPUd~&EL
Yxy!&hPLv:
public void setSSiteURL(String value) 9oIfSr,y
{ Sk:x.oOZ
sSiteURL = value; :|8!w
} Apj[z2nr
I5)$M{#a
B" _Xst
public String getSFilePath() X#Ob^E%J
{ Qsw.429t
return sFilePath; VCVKh
} %g^:0me`
}t:*w
cY Qm8TR<
public void setSFilePath(String value) /E3~z0
{ 'y5H%I!
sFilePath = value; (&u'S+
} C\Z5%2<Z
[aG
OsW*@v(
public String getSFileName() 8 &v)Vi-
{ &O#1*y Z
return sFileName; )?I*zc
} f$5\ b[O
qA[cF$CIl)
<2fy(9y
public void setSFileName(String value) =**Q\Sl
{ %%#bTyF
sFileName = value; ;.<HpDfG_
} 24 .'+3
Jz*A!Li
cj^hwtx
public int getNSplitter() u{w,y.l1h
{ 0x<G\ l4
return nSplitter; Q5l+-
} %eh.@8GL`
]826kpq_
j<6+p r
public void setNSplitter(int nCount) |j{]6Nu
{ g[HuIn/
nSplitter = nCount; ^go3F{;4i
} oad /xbp@/
} $e{[fmx
7G7"Zule*j
pe>?m^gz[
/* Jw>na _FJ
**Utility.java 2kk; z0f
*/ OOXP1L
package NetFox; -%Ce
=diGuIB
rg=Ym.
public class Utility { K`j:F>b
$~j9{*]5
IxG7eX!
public Utility() )/Gi-::
{ O<$j}?2
=q|//*t2
:Rnwyj])
} nywC]T
ep0dT3&
//线程睡眠 <r(D\rmD
public static void sleep(int nSecond) :6&#u.\u
{ ]"?<y s
try{ /1D.Ud^
Thread.sleep(nSecond); i)Q d>(v
} G'';VoW=
catch(Exception e) 0P{8s
{ .>~er?-
e.printStackTrace (); NxDVU?@p*
} 3lEP:Jp
} aR'~=t&;z1
ori[[~OyB
//日志 ImD&~^-_<
public static void log(String sMsg) 'NCx<0*
{ VR%*8=
System.err.println(sMsg); ,rF!o_7
} G:wO1f6
3OY(L`
&}|`h8JA]K
public static void log(int sMsg) @?;)x&<8?3
{ JoZzX{eu"
System.err.println(sMsg); :Bu)cy#/[
} _meW9)B
} sY?wQ:
rx@i.+
!,rF(pz
/* D~|q^Ms,%
**TestMethod.java 5*Qzw[[=
*/ Y7 K2@257
package NetFox; k7L4~W
rz2,42H]
${}9/(x/^
public class TestMethod { 2- (}=N
B@*!>R
:#{0yno)H
public TestMethod() Iz;^D!
{ ///xx/weblogic60b2_win.exe Q`Q"p
try{ `*`ZgTV
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #l.s>B4
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); OECVExb@eH
SiteFileFetch fileFetch = new SiteFileFetch(bean); yu>;m.e_
fileFetch.start(); J!dv"Ww"
} 6+"gk(
catch(Exception e){e.printStackTrace ();} -w8?Ur1x:
j~>J?w9<O
&.#dZ}J
} h?}S|>9
T&bB8tQk
hd[t&?{=
public static void main(String[] args) Fg'{K%t4
{ \" m&WFm
new TestMethod(); \OWxf[
} x{GFCy7
} tw.z5
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