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)); 8:x{
} .+;;-]})
for(int i=0;i<nEndPos.length-1;i++) AB!P(
{ wVSk.OOB
nEndPos = nStartPos[i+1]; vy <(1\
} u@;6r"8q
nEndPos[nEndPos.length-1] = nFileLength; Y[hTO.LF
} GE2^v_
} OwdA6it^f
B.e3IM0
3C+!Y#F
//启动子线程 qqmhh_[T
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; G,VTFM6
for(int i=0;i<nStartPos.length;i++) J FYV@%1~
{ iiWs]5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MDHTZ94\Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), j~|pSu.<
nStartPos,nEndPos,i); Zj(2$9IU
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !e+^}s
fileSplitterFetch.start(); X^?M4
} r#%e$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dB{VY+!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7S +YQ$_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", tAI<[M@
nEndPos = " + nFileLength); D7D:?VoR
// fileSplitterFetch[nPos.length-1].start(); |f:1Br
4x`.nql
7K 8tz}
//等待子线程结束 kw%vO6"q(
//int count = 0; #J=@} S)
//是否结束while循环 sPu@t&$
boolean breakWhile = false; :o)4Y
SuO@LroxTB
jD`p;#~8
while(!bStop) }m`+E+T4
{ (M>[D!Yt
write_nPos(); 8Pkw'.r
Utility.sleep(500); 'aW}&!H M
breakWhile = true; pb\W7G
i9QL}d
d0b`qk @4
for(int i=0;i<nStartPos.length;i++) *0*1.>Vg
{ LD.^.4{c:
if(!fileSplitterFetch.bDownOver) ._6|epJ#
{ x#-+//
breakWhile = false; M%\=Fb
break; -naj.omG|
} y<Z-f.
} l]bCt b%_
if(breakWhile) uT#MVv~.
break; 2[O\"a%
@(~m.p|
eSC69mfD
//count++; p+t79F.js
//if(count>4) ggy 7p44
// siteStop(); `T-lBwH
} ,h#U<CnP#
7%%FYHMO:
"K!9^!4&
System.err.println("文件下载结束！"); p^E}%0#
} T%opkyP>=
catch(Exception e){e.printStackTrace ();} FL,av>mV
} zvDg1p
r8k.I4
7AOjlC9R}
//获得文件长度 |X'Pa9u
public long getFileSize() Uu<Tn#nb
{ "EE=j$8u+
int nFileLength = -1; {m<NPtp910
try{ lrE|>R
URL url = new URL(siteInfoBean.getSSiteURL()); z.xOT;t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =VctG>ct|
httpConnection.setRequestProperty("User-Agent","NetFox"); \0^ZNa?
f:).wi Ld
:We}l;.jQ
int responseCode=httpConnection.getResponseCode(); Wl4T}j
if(responseCode>=400) c^$+=-G{fd
{ (I) e-1
processErrorCode(responseCode); PN +<C7/
return -2; //-2 represent access is error fV\ eksBF
} L, k\`9bQ
gLH#UwfJ
M<sY_<z
String sHeader; .2si[:_(p
=Y0>b4
.ZB/!WiF
for(int i=1;;i++) B F,rZZL
{ dp&bcR&#)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .&Vyo<9Ck
//Utility.log(in.readLine()); #hNp1y2
sHeader=httpConnection.getHeaderFieldKey(i); tSZd0G<A<o
if(sHeader!=null) 5GwXZ;(G
{ N?7vcN+-t)
if(sHeader.equals("Content-Length")) X53TFRxnT
{ 0( s io\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); w'Cn3b)`
break; 5T,In+~Kd
} P/'9k0zs)
} j.5;0b_L^
else q*h1=H52
break; :=0XT`iY
} @aA1=9-L
} -quWnn/
catch(IOException e){e.printStackTrace ();} CQLh;W`Dc
catch(Exception e){e.printStackTrace ();} XO=UKk+EK
R m{\ R
@rTAbEk{U
Utility.log(nFileLength); p PF]&:&-b
LPOZA`
$p} /&
return nFileLength; jv"^_1
} y[}O(
)ny,vcU]
Rj/9\F3H
//保存下载信息（文件指针位置） T}?vp~./
private void write_nPos() w'Kc#2
{ ddR_+B*H
try{ w84 ]s%y
output = new DataOutputStream(new FileOutputStream(tmpFile)); E rf$WPA
output.writeInt(nStartPos.length); Cw=wU/)
for(int i=0;i<nStartPos.length;i++) dXe. 5XC
{ ,r,~1oV<"
// output.writeLong(nPos); w(P\+ m<%
output.writeLong(fileSplitterFetch.nStartPos); UacGq,
output.writeLong(fileSplitterFetch.nEndPos); ATeXOe
} A5lP%&tu(
output.close(); 3,snx4q (
} pY3N7&m\:
catch(IOException e){e.printStackTrace ();} Ozygr?*X
catch(Exception e){e.printStackTrace ();} ~okIiC]#
} bi fi02
G]Jchg <
8\M%\]_
//读取保存的下载信息（文件指针位置） ~)S Q{eK?&
private void read_nPos() pearf2F
{ ^jO$nPDd
try{ $ljgFmR_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?|i6]y=D
int nCount = input.readInt(); /f_c?|
nStartPos = new long[nCount]; J.`z;0]op
nEndPos = new long[nCount]; KAR XC,z
for(int i=0;i<nStartPos.length;i++) j15TavjGh
{ ^UF]%qqOn
nStartPos = input.readLong(); fs]9HK/@\
nEndPos = input.readLong(); ,tEvz
} 8Ee bWs*1
input.close(); 6zQ {Y"0
} A%VBBvk
catch(IOException e){e.printStackTrace ();} A2`QlhZ
catch(Exception e){e.printStackTrace ();} bb6 ~H
} ;|2h&8yX(/
sP0pw]!
dBV^Khf J
private void processErrorCode(int nErrorCode) u@`)u#
{ cx]O#b6B.
System.err.println("Error Code : " + nErrorCode); ZKGS?z
} $z7[RLu0!
9`8\<a'rU
+[ _)i9a
//停止文件下载 '~-Lxvf'
public void siteStop() !;SpQ28
{ WC!bB
bStop = true; E)Z$7;N0x
for(int i=0;i<nStartPos.length;i++) 8ycmvpJ
fileSplitterFetch.splitterStop(); )shzJ9G
Fr%LV#Q
&`a$n2ycy
} W|U!kqU
} h(,SAY_
//负责部分文件的抓取 hT&,5zaWdv
**FileSplitterFetch.java {&Kq/sRz
*/ 5zlgmCGow
package NetFox; guC/eSxv
i^{.Q-
c<V.\y0x
import java.io.*; r<;bArs-u
import java.net.*; W{OlJRX8
^n@.
p}KZ#"Q
public class FileSplitterFetch extends Thread { eSynw$F2N
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&bx;GG\<4
String sURL; //File URL YyX/:1 sg>
long nStartPos; //File Snippet Start Position \TG!M]D:
long nEndPos; //File Snippet End Position n:?fv=9n
int nThreadID; //Thread's ID ^4LkKYMS
boolean bDownOver = false; //Downing is over F|*{Ma
boolean bStop = false; //Stop identical R v9?<]
FileAccessI fileAccessI = null; //File Access interface a;Ic!:L
{~yj]+Im
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =*.Nt*;;
{ 4z-sR/d
this.sURL = sURL; EXDtVa Ot
this.nStartPos = nStart; j%iz>
this.nEndPos = nEnd; dbkccO}WB
nThreadID = id; %3e}YQe)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \?[#>L4
} 3,j)PKf ;
-OpI,qyS
4#uWj?u
public void run() PsDks3cG
{ ?)#dP8n
while(nStartPos < nEndPos && !bStop) b 2n.v.$G
{ p\o=fcH%E
+dm&XW >
pmyHto"
try{ J/j1Yf'9
URL url = new URL(sURL); 09"C&X~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wVBY^TE
httpConnection.setRequestProperty("User-Agent","NetFox"); w>T1D
String sProperty = "bytes="+nStartPos+"-"; eI?<*
httpConnection.setRequestProperty("RANGE",sProperty); ^*C+^l&J!
Utility.log(sProperty); sXI_!)H
C~vU
*LeFI%
InputStream input = httpConnection.getInputStream(); Ebp^-I9.d
//logResponseHead(httpConnection); 8NJ(l
U">D_ 8
4NL TtK
byte[] b = new byte[1024]; 2Z6#3~
int nRead; RqW ZhHI1M
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) lhTjG,U=
{ ~=HN30
nStartPos += fileAccessI.write(b,0,nRead); ?eT^gWX
//if(nThreadID == 1) #d%'BUde
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <Mo_GTOC!
} q{ov62t`
< vU<:S
>#B%gxff
Utility.log("Thread " + nThreadID + " is over!"); _3h(R`VdWO
bDownOver = true; m;{_%oQ;
//nPos = fileAccessI.write (b,0,nRead); E;~gQ6vAI
} (7x5
catch(Exception e){e.printStackTrace ();} I,vy__sZ
} $ud5bT{n
} C$\|eC j
[AQ6ads)
;A~S){
//打印回应的头信息 ,St#/tu
public void logResponseHead(HttpURLConnection con) >e*m8gm#
{ 6} !n0
for(int i=1;;i++) QRXsLdf$$
{ O>xGH0H
String header=con.getHeaderFieldKey(i); =6imrRaaV
if(header!=null) KDgJ~T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a ^<W ?Z
Utility.log(header+" : "+con.getHeaderField(header)); T5NO}bz
else O5{!CT$
break; ^ruS
} t>f<4~%MJ
} UA/Q3)
jDIO,XuF
! lgsV..R
public void splitterStop() esx<feP)\
{ AU}e^1h
bStop = true; y7dnXO!g9-
} ,i#]&f`c;5
{MU>5\
LGKkT?fcSC
} ~T>_}Q[M2p
G+ PBV%gE[
1w'iD X
/* G!T)V2y
**FileAccess.java vC[)/w
*//文件访问(定位，写) 7$WO@yOsh
package NetFox; d_gm'
import java.io.*; F=yrqRS=
L B1ui
#ebT$hf30
public class FileAccessI implements Serializable{ G^!20`p:
]R\k@a|G
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L)&?$V
RandomAccessFile oSavedFile; CUfD[un2D
long nPos; Um]>B`."wK
u&?J+
]78I
public FileAccessI() throws IOException cW;to Q!P
{ /=>z|?z3
this("",0); :M9'wg
} n^'ip{
.5|AX6p+^
qPuxYU
public FileAccessI(String sName,long nPos) throws IOException ]=of=T:
{ ==`K$rM
oSavedFile = new RandomAccessFile(sName,"rw"); [[P?T^KT
this.nPos = nPos; yZ)GP!cM4c
oSavedFile.seek(nPos); `YAqR?Xj_<
} %50}oD@
P}N%**>`
}legh:/*?O
public synchronized int write(byte[] b,int nStart,int nLen) %YG ~ql
{ GJai!$v
int n = -1; PF*<_p"j
try{ Q]Q i
oSavedFile.write(b,nStart,nLen); `DIIJ<;g
n = nLen; ^-cj=on=Q
} hNmC(saMGm
catch(IOException e) A U9Y0<
{ GLQ1rT
e.printStackTrace (); JDfkm+}uY
} |4aV~n[>#
f!a[+^RB:
Q ,30
return n; LOpnPH`
} qEPvV
yjvzA|(YC
6 /gh_'&
} ]]`hnzJX
]?S\So+
z]^&^VFu
/* \k/ N/&;
**SiteInfoBean.java t%ye:
*/ f1(V~{N,+
package NetFox; c<L^ 1,G2
{[hH: \
PN[ `p1F
public class SiteInfoBean { 1%Xwk2l,8b
uFOxb}a9v
m5Q,RwJ!xK
private String sSiteURL; //Site's URL &$tBD@7
private String sFilePath; //Saved File's Path `}#(Ze*V:
private String sFileName; //Saved File's Name <#<4A0:
private int nSplitter; //Count of Splited Downloading File QCQku\GLV
IlG)=?8XZ
Wz}RJC7p
public SiteInfoBean() _*h,,Q
{//nSplitter的缺省值为5 35B G&;C
//default value of nSplitter is 5 @G[P|^B
this("","","",5); 0b+OB pqN
} ~[dU%I>L^
2Un~Iy
1OK,r`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <DP_`[+C
{ dqO!p6
sSiteURL= sURL; _"_ W KlN
sFilePath = sPath; zOD5a=[1
sFileName = sName; X>:@`}bq
this.nSplitter = nSpiltter; #XR<}OYcL
Hq[d!qc
)kR~|Yn<-
} /KjRB_5~q}
)QEvV:\
W.TZU'%
public String getSSiteURL() 87P{vf#
{ l_GvdD
return sSiteURL; dOh'9kk3
} 8rwkux >
=G3O7\KmH
S453oG"
public void setSSiteURL(String value) l?v`kAMR
{ 4zs1BiMG
sSiteURL = value; x*& OvI/o
} RQ}(}|1+\
q+f]E&':
gQ4Q h;
public String getSFilePath() La9v97H:
{ 8aZuI|z
return sFilePath; i <0H W
} |@?B%sY
a3e<<<Z>R
|6w.m<p
public void setSFilePath(String value) c9imfA+e
{ &QO~p3M
sFilePath = value; 0yr=$F(]s
} RFd.L@-]
,g2|8>sJP
Z3?,r[
public String getSFileName() V{@ xhW0
{ :Y/i%#*1
return sFileName; :=vB|Ch:~
} HSGM&!5mW
c=]qUhnH
w6DK&@w`'/
public void setSFileName(String value) Ry>c]\a]
{ @r4ZN6Wn
sFileName = value; z2Sp
} {vYmK#}
Dz/I"bZLC
JR{3n*
public int getNSplitter() <Z5ak4P
{ KD?~ hpg
return nSplitter; `l,=iy$
} 3"=%[
0jCYOl
^{&Vv(~!Q
public void setNSplitter(int nCount) H?98^y7
{ +shT}$cb1
nSplitter = nCount; ;@p2s'(
} OrP-+eg
} sW!pMkd_
#k2&2W=x
j~,7JJ (y
/* CqX2R:#
**Utility.java Li~(kw3
*/ lxoc.KDtR
package NetFox; cAq>|^f0a
2GOQ|Z
&09z`*,
public class Utility { u4TU"r("A
oT2h'gu")
KtzoL#CT
public Utility() -5,QrMM<
{ @w&VI6
p48M7OV
0STtwfTr:
} 'teToE<i
PmOm>
//线程睡眠 )1ia;6}
public static void sleep(int nSecond) 7[5g_D t
{ Gxu
try{ 2|]$hjs
Thread.sleep(nSecond); Qr]xj7\@i
} Q4e*Z9YJ
catch(Exception e) H&jK|]UXoO
{ Sx)b~*
e.printStackTrace (); `:cnu;
} DpjiE/*
} }[ LME Z
tWR>I$O8F
//日志 >Ia{ZbQV
public static void log(String sMsg) ]-"~?
{ s\ft:a@
System.err.println(sMsg); $z,lq#zzl
} j<H`<S
lx*"Pj9hho
~_ss[\N
public static void log(int sMsg) USfpCRj9
{ [of{~
System.err.println(sMsg); \Z9+U:n
} hZNS$
} H.|v^e
~]f+
KdU!wsKfG
/* &!> )EHGV
**TestMethod.java ,l`4)@{G
*/ x95[*[
package NetFox; t mAj
g a|RW0
am,UUJ+h>
public class TestMethod { rFJ(t7\9h
7U68|\fI!
Nd!0\ "AE
public TestMethod() 4_qd5K+n"
{ ///xx/weblogic60b2_win.exe ; (I(TG
try{ Ut:>'TwG
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lc1?Vd$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); SrGX4
SiteFileFetch fileFetch = new SiteFileFetch(bean); |uo<<-\jTO
fileFetch.start(); 1{@f:~v?
} Uywi,9f
catch(Exception e){e.printStackTrace ();} !K a!f1
>DX\^86x
q\wT[W31@
} t.wB\Kmt\
1L722I@
ph\KTLU
public static void main(String[] args) 0>hV?A
{ F FHk0!3
new TestMethod(); P,5gaT)
} J6pQ){;6
} q]Y [W1
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