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)); }\\KYyjY
} }:us:%
for(int i=0;i<nEndPos.length-1;i++) @?yX!_YC
{ KKiE@_z
nEndPos = nStartPos[i+1]; 18+)`M-5o
} w5Ay)lz
nEndPos[nEndPos.length-1] = nFileLength; BD_Iz A<wK
} .Le?T&_
} WtG~('g>&
GO`Ru 8
$\]&rZVi
//启动子线程 ]:4*L
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ju96#v+:
for(int i=0;i<nStartPos.length;i++) @~!wDDS
{ 8FKXSqhVM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5=v}W:^v.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), RS)tO0
nStartPos,nEndPos,i); $~VRza 8Q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K 1 a\b"
fileSplitterFetch.start(); 1IC~e^"
} 5ni~Q 9b
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T 6)bD&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6p?,(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5nT"rA
nEndPos = " + nFileLength); jbVECi-
// fileSplitterFetch[nPos.length-1].start(); iOU6V
mz,
3I)VHMC
//等待子线程结束 gkES5Q
//int count = 0; ="Ho%*@6
//是否结束while循环 (tIo:j
boolean breakWhile = false; gy#/D& N[
xJ>fm%{5
OBOtuu.
while(!bStop) Fl kcU `j
{ 9 7GV2]-M
write_nPos(); YG3J$_?y0
Utility.sleep(500); 'gC_)rK*
breakWhile = true; kCR_tn 4
o4m\~as)Y
/178A;Jy
for(int i=0;i<nStartPos.length;i++) H*ow\ Ct
{ ([SU:F!uW(
if(!fileSplitterFetch.bDownOver) }001K
{ bCo7*<I4
breakWhile = false; fZ0M%f
break; (.D~0a JU
} Si8pzd
} }uJu>'1[G
if(breakWhile) ABQ('#78
break; ';3{T:I
C-Q28lD}f
fI&t]
//count++; U>]$a71
//if(count>4) _I@9HC 4
// siteStop(); }=<
} YC++&Nk
;j[>9g
h"X;3b^ m
System.err.println("文件下载结束！"); .E`\MtA
} |bTPtrT8
catch(Exception e){e.printStackTrace ();} T ]t'39
} ZA0mz 65
hIy~B['
B"h#C!E
//获得文件长度 63\/ * NNB
public long getFileSize() 7HIeJ
{ w65K[l;2
int nFileLength = -1; K2TcOFQ
try{ J]{QB^?
URL url = new URL(siteInfoBean.getSSiteURL()); ]^h]t~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Uwf+
httpConnection.setRequestProperty("User-Agent","NetFox"); yv t.
L 6c 40
>V-A;S:
int responseCode=httpConnection.getResponseCode(); O_`VV*
if(responseCode>=400) }Yb[
{ IpYM;tYw&
processErrorCode(responseCode); pMw*9sX
return -2; //-2 represent access is error Q6PHpaj
} 4!Fo$9
NjVYLn<.r
'@o;-'b
String sHeader; ]<ldWL
) i;1*jK
~IYUuWF(
for(int i=1;;i++) - Ajo9H
{ zQcL|(N
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r)y=lAyF>
//Utility.log(in.readLine()); Y~c|hfL
sHeader=httpConnection.getHeaderFieldKey(i); J\+0[~~
if(sHeader!=null) &XIt5<$~R
{ [w0QZyUn
if(sHeader.equals("Content-Length")) |XQIfW]A
{ 3@kf@Vf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Bmr>n6|
break; uGwm r
} .B7,j%1r
} \H1(PA
else mWoAO@}Y
break; o} J&E{Tk
} "|EM;o
} /sx@$cvW
catch(IOException e){e.printStackTrace ();} JZ)RGSG i
catch(Exception e){e.printStackTrace ();} )#?"Gjf~
j'Gt&\4
PQy4{0 _
Utility.log(nFileLength); a!a-b~#cx
T-.%
z>LUH
return nFileLength; /Lfm&;
} ;Y00TGU
2^r<{0@n
(up~[
//保存下载信息（文件指针位置） w mn+
private void write_nPos() ]OM"ZG/^
{ c/D+|X*
try{ ?4+9fE<Q
output = new DataOutputStream(new FileOutputStream(tmpFile)); } df W%{
output.writeInt(nStartPos.length); 5 h-@|t
for(int i=0;i<nStartPos.length;i++) ^]H5h]U'
{ f86XkECZ;`
// output.writeLong(nPos); y&6FybIz
output.writeLong(fileSplitterFetch.nStartPos); `95r0t0hh\
output.writeLong(fileSplitterFetch.nEndPos); abuh`H#
} Vx$\hcG
output.close(); WJQvB=D&
} +9M^7/}H
catch(IOException e){e.printStackTrace ();} :0Bq^G"ge
catch(Exception e){e.printStackTrace ();} \HqNAE2T
} t)~"4]{*}D
SEo'(-5
tI`Q/a5@
//读取保存的下载信息（文件指针位置） $mu^G t
private void read_nPos() *1uKr9
{ 52%2R]G!
try{ vmU@^2JSJ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vx1c,8
int nCount = input.readInt(); '.on)Zd.
nStartPos = new long[nCount]; Dt}JG6S
nEndPos = new long[nCount]; M\o9I
for(int i=0;i<nStartPos.length;i++) ZT'`hK_up
{ }u\])I3
nStartPos = input.readLong(); $:8x(&+/@
nEndPos = input.readLong(); V\>K]mwD
} 1ct;A_48
input.close(); /$i.0$L
} <NR#Y%}-V
catch(IOException e){e.printStackTrace ();} bfFeBBi
catch(Exception e){e.printStackTrace ();} zZ7;jyD
} b+%f+zz*h
3_ r*y9l
r A`V}>Xj
private void processErrorCode(int nErrorCode) CnU*Jb
{ uW=k K0E
System.err.println("Error Code : " + nErrorCode); o m^0}$V
} A#K14Ayr
ERUz3mjA/
]_Vx{oT7
//停止文件下载 ~Y`ldL
public void siteStop() ,`|3KE9
{ lsJSYJG&
bStop = true; LzG%Z1`
for(int i=0;i<nStartPos.length;i++) A0/"&Ag]
fileSplitterFetch.splitterStop(); &TnS4O
S*==aftl(
rx'RSo#1O
} cA2V2S)
} - \5v^l
//负责部分文件的抓取 s6H]J{1F
**FileSplitterFetch.java RM]\+BK
*/ o\[~.";Z
package NetFox; NokU)O;x
]q;Emy
@fHi\W2JG
import java.io.*; '<jyw
import java.net.*; u#Pa7_zBj]
#pT"BSz]
Vrjc~>X
public class FileSplitterFetch extends Thread { -c_74c50
viW!,QQ(S
]}Mj)J"m
String sURL; //File URL US+Q~GTA
long nStartPos; //File Snippet Start Position .?D7dyU l1
long nEndPos; //File Snippet End Position f~t:L,\,
int nThreadID; //Thread's ID ^?-:'<4q$
boolean bDownOver = false; //Downing is over Qk0R a_
boolean bStop = false; //Stop identical V39g,=`b%
FileAccessI fileAccessI = null; //File Access interface ?[VM6- &
-j+UMlkB
4~ q5,^kgB
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException pf2[,v/
{ ]jtK I4
this.sURL = sURL; J}*,HT*
this.nStartPos = nStart; qaqBOHI6G
this.nEndPos = nEnd; z#8~iF1
nThreadID = id; 'OE&/ C[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p?{Xu4(
} ED2a}Tt>Z
O)C\vF#
zE336
public void run() N"pc,Q\xU
{ H~oail{EQ
while(nStartPos < nEndPos && !bStop) 5/q}`T9i%7
{ cCSs
fWCo;4<5?
x5|I
try{ xN>npP
URL url = new URL(sURL); GX)u|g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w~.f
httpConnection.setRequestProperty("User-Agent","NetFox"); _A M*@|p,
String sProperty = "bytes="+nStartPos+"-"; l3KVW5-!gS
httpConnection.setRequestProperty("RANGE",sProperty); !xzeMVI
Utility.log(sProperty); O6Vtu Ws%
$CxKuB(
Yw22z #K
InputStream input = httpConnection.getInputStream(); sWQfr$^A
//logResponseHead(httpConnection); `uq8G
&Q9qq~
KLU-DCb%
byte[] b = new byte[1024]; bADnW4N`6;
int nRead; 8J*"%C$qe
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) TIx|L
{ Eou~P h*t
nStartPos += fileAccessI.write(b,0,nRead); CWf /H)~
//if(nThreadID == 1) a[v0%W ]u
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5uGqX"
} ZWii)0'PV
t#yk->,
G !<Z.]
Utility.log("Thread " + nThreadID + " is over!"); ~Xw"}S5
bDownOver = true; -B>++r2A^
//nPos = fileAccessI.write (b,0,nRead); 5(Cl1Yse=r
} t![7uU.W
catch(Exception e){e.printStackTrace ();} tN[L@t9#cr
} ylUrLQ\
} x"eRJii?
7.-V-?i
anuL1fXO
//打印回应的头信息 BoA/6FRi[
public void logResponseHead(HttpURLConnection con) R7]l{2V#^
{ k=2Lo
for(int i=1;;i++) =31"fS@
{ *zNYZ#
String header=con.getHeaderFieldKey(i); V @rI`~$
if(header!=null) %`k6w3qI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [l:x'_y
Utility.log(header+" : "+con.getHeaderField(header)); VJ84?b{c W
else pb^i^tA+A
break; m9)p-1y@5
} 6f;fx}y
} uzXCIv@
iz5CAxm
'#! gh?
public void splitterStop() vrl;"Fm+
{ d[[]PX
bStop = true; cD@(/$wt
} )W|w C#
-T!f,g3vW
~"dA~[r L
} 4pe'06:
_t:$XJ`bTk
6L:x^bM
/* r)qnl9?;`]
**FileAccess.java "vA}FV%tRq
*//文件访问(定位，写) jnd[6v=C7-
package NetFox; 5NBV[EP
import java.io.*; U6=..K!q
\%u3
}{M#EP8q+
public class FileAccessI implements Serializable{ PxF<\pu&
U!T~!C^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 WJ)z6m]
RandomAccessFile oSavedFile; w'L\?pI
long nPos; mrTlXXz
A+HF@Uw}^
\Fl+\?~D
public FileAccessI() throws IOException h"lX4
{ $GYm6x\4
this("",0); ko1J094Y%
} !P ~_Dl2d
EQ2#/>
PiYY6i0
public FileAccessI(String sName,long nPos) throws IOException 6\L0mcXR!
{ @HT% n
oSavedFile = new RandomAccessFile(sName,"rw"); {-ZFp
this.nPos = nPos; jNu9KlN
oSavedFile.seek(nPos); Yv hA_v
} z MLK7+
b6W2^tr-
Y_}mYvJW
public synchronized int write(byte[] b,int nStart,int nLen) uB |Ss
{ `/_o!(Z`
int n = -1; r/& sub"X
try{ ktI/3Mb@
oSavedFile.write(b,nStart,nLen); n 9\ C2r
n = nLen; )iq-yjO6
} X7[^s $VK
catch(IOException e) YNYx>Ue
{ pa#d L!J
e.printStackTrace (); 5>VY LI
} "-_fv5jL
p/(~IC"!J
t'9*R7=
return n; u?>B)PW
} N03G>fZ
V7#Ffi
6W@UJx}w5
} L{:9Cx!F
Tskq)NU
Pa(^}n|
/* `IOs-%s
**SiteInfoBean.java pnMEB,)
*/ MzPzqm<
package NetFox; rI^zB mrr
r~+\ Y"rM
g wz7krUTe
public class SiteInfoBean { rX*H)3F
Jm|+-F@I
A"`foI$0
private String sSiteURL; //Site's URL %cCs?ic
private String sFilePath; //Saved File's Path "8'@3$>R=
private String sFileName; //Saved File's Name s?zAP O8Sz
private int nSplitter; //Count of Splited Downloading File }>)@WL:q
fKp#\tCc y
^BUYjq%(`
public SiteInfoBean() c;{Q,"9U
{//nSplitter的缺省值为5 |"XPp!_uN
//default value of nSplitter is 5 :]rJGgK#
this("","","",5); 3VI4X
} lAzjN~V
*"WDb|PBb
J\J?yo 6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7uT:b!^f[
{ aUxGzMZ
sSiteURL= sURL; [v$0[IuY,
sFilePath = sPath; a,3j,(3
sFileName = sName; cHcmgW\4
this.nSplitter = nSpiltter; J~B<7O<?!1
7Q7-vx
e2z h&j
} $p#%G#T
kgy:Q'
4VHqBQ4
public String getSSiteURL() PGYXhwOI
{ .w> 4
return sSiteURL; L,SGT8lL
} dcLA1sN,
%ThyOl@O
fq5_G~c=
public void setSSiteURL(String value) ONx(]
{ }K1JU`Lz
sSiteURL = value; "8~:[G#
} Glxuz0]
=1O<E
O$D'.t
public String getSFilePath() iv?gZg
{ 4 SHU
return sFilePath; Rop'e8Q
} MS>t_C(
O:TlIJwW
Q?8R[i
public void setSFilePath(String value) CqHK%M
{ Rp*R:3 C
sFilePath = value; nt;haeJ
} @mE)|.f
af#pR&4}
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public String getSFileName() t|9 GS|
{ |u0(t,T
return sFileName; AtU v71D:
} CNQC^d\ h
TT50(_8
XW -2~?$
public void setSFileName(String value) X/z6"*(|/
{ zUkN 0
sFileName = value; YoN*:jB<M
} bV edFm
?pYKZg/c
U7!.,kR-
public int getNSplitter() %|^OOU}
{ )x}l3\s
return nSplitter; %{(x3\ *&
} hX`hs-*qM
:ml2.vP
56e r`=ms
public void setNSplitter(int nCount) ~/8M 3k/
{ 7M<'ddAN
nSplitter = nCount; `W dD8E
} 1QcT$8HA
} gXonF'
GuGOePV
@HRC\OG
/* ,ldI2]
**Utility.java %9k!A]KD
*/ {cB+mh;mJ>
package NetFox; aFe`_cnG
{K4+6p
:C}2=
public class Utility { ,*&G1|_6
R+nMy=I%8
fwrJ!j
public Utility() ddfs8\
{ u)ev{)$TM
JJltPGT~Oa
A a=u+
} t~E<j+<2B
Z.W66\8~}^
//线程睡眠 s[K^9wz
public static void sleep(int nSecond) V?P,&c?84
{ 4Ue_Y'LmM
try{ a 4=N9X
Thread.sleep(nSecond); Cw~RJ^a_
} cTXri8K_
catch(Exception e) "S&@F/
{ iT;@bp
e.printStackTrace (); DHw&+MY
} aM@z^<Ub
} lqowG!3H
K,6b3kk
//日志 N0K){
public static void log(String sMsg) uQ=^~K:Z~
{ )J_\tv
System.err.println(sMsg); ew;ur?
} ]J* ,g,
-DN8Yb
cFN'bftH4
public static void log(int sMsg) EyI}{6~F
{ 4-kZJ\]
System.err.println(sMsg); `}m Q
} JXixYwm
} ~`GhS<D
ik"sq}u_]E
l"q1?kaVg
/* BnCKSg7V
**TestMethod.java ed!:/+3e/
*/ ?E9DXg
package NetFox; &O)&k
?9HhG?_x
+vNZW@_$D
public class TestMethod { !" JfOu
yMZHUd
Ja]?&j
public TestMethod() Z1ALq5
{ ///xx/weblogic60b2_win.exe ui"3ak+F
try{ 'DCFezdf3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0x11 vr!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); '=E3[0W
SiteFileFetch fileFetch = new SiteFileFetch(bean); uk9g<<3T
fileFetch.start(); !PMU O\y
} &SAH2xR
catch(Exception e){e.printStackTrace ();} c(U
[w0/\]o
@v}B6j b;
} LuR,f"%2
$s4Wkq
_TUk(Qe
public static void main(String[] args) @)>D))+
{ uK("<u|
new TestMethod(); zf.-I
} }C /]
} :^'O}2NP
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