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)); ;9MIapfUd(
} tD^$}u6
for(int i=0;i<nEndPos.length-1;i++) D[p_uDIz
{ l=&\luNz
nEndPos = nStartPos[i+1]; qtR/K=^i
} )U|0vr8:
nEndPos[nEndPos.length-1] = nFileLength; [AHoTlPZ
} R4_BP5+
} pQ,|l$^m
W?H-Ng3E
R$m?aIN
//启动子线程 |S6L[Uo
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Au10]b
for(int i=0;i<nStartPos.length;i++) n@=D,'cn
{ XpH d"(*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]mR!-Fqj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), mI>=S
nStartPos,nEndPos,i); t) uS7y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /1BqC3]tL
fileSplitterFetch.start(); )+ (GE
} gmUX 2x(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vqhu%ZyP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ooA%/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B<{Yj}..
nEndPos = " + nFileLength); e;8nujdG"
// fileSplitterFetch[nPos.length-1].start(); A$jf#,
A.+Qa
%#7 ]
//等待子线程结束 "}Oj N\
//int count = 0; y9U*E80q{
//是否结束while循环 _aP2gH
boolean breakWhile = false; ~ugyUpY"
Y3.^a5o
jdf3XTw
while(!bStop) G,X>f?
{ 2cQG2N2*
write_nPos(); *{!E`),FX
Utility.sleep(500); e3.q8r
breakWhile = true; 5~FXy{ZIH
/B!Ik:c}
Ba}<X;B}
for(int i=0;i<nStartPos.length;i++) GdVrl[
{ YH,u*.I^/
if(!fileSplitterFetch.bDownOver) g1{2E<b5
{ =3;~7bYO
breakWhile = false; $DeVXW
break; v*JXrB&x
} miUjpXt
} "Z]z9(
if(breakWhile) ~.$ca.Gf
break; @[v4[yq-
*J3Z.fq%:i
%~I%*=o[
//count++; 2l}H=DZV
//if(count>4) Oj1B @QE
// siteStop(); r7+Ytr
} G%MdZg&i
MlV3qM@
B=)tq.Q7
System.err.println("文件下载结束！"); ih=O#f|
} )mu[ye"p
catch(Exception e){e.printStackTrace ();} BIxjY!!"
} m\f}?t
y:YJv x6&4
q0*d*j F0u
//获得文件长度 CwaW>(`v
public long getFileSize() u= Vt3%q
{ o(stXa
int nFileLength = -1; H~;s$!lG
try{ (R]b'3,E$
URL url = new URL(siteInfoBean.getSSiteURL()); n{"e8vQx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JN-W`2
httpConnection.setRequestProperty("User-Agent","NetFox"); -ZH6*7!
dO!B=/
8SN4E
int responseCode=httpConnection.getResponseCode(); !@T5](zV
if(responseCode>=400) LMaY}m>
{ MDauHtF,
processErrorCode(responseCode); GhR%fxe
return -2; //-2 represent access is error AP9>_0=
} (5GjtFojY|
"+A8w
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String sHeader; LAH.PcjPa
.R_-$/ZP
cH`ziZ<&m1
for(int i=1;;i++) UIo jXR<
{ 8Z>=sUMQ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); MI,kKi
//Utility.log(in.readLine()); (/jZ&4T
sHeader=httpConnection.getHeaderFieldKey(i); ]6].l$%z#
if(sHeader!=null) ;3&HZq6Z (
{ 15_Px9
if(sHeader.equals("Content-Length")) +:&|]$8<
{ FvVM}l'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Rg7~?b-
break; [orS-H7^
} fzr0dcNgM
} "H|hN
else lNx:_g:SrZ
break; *n_7~ZX
} |W*i'E
} Vi>`g{\
catch(IOException e){e.printStackTrace ();} evlz R/
catch(Exception e){e.printStackTrace ();} uF\ ;m.
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]5+<Rqdbg
Utility.log(nFileLength); R]" jr
pwmH(94$0
-Q" N;&'[&
return nFileLength; i\C~]K~O!
} =2/[n8pSsM
Y))x'<T'Q
?@H/;hB[|
//保存下载信息（文件指针位置） y\mK?eR
private void write_nPos() (3N;-
{ LfX[(FP
try{ >#|%y>g .o
output = new DataOutputStream(new FileOutputStream(tmpFile)); PvW~EJ
output.writeInt(nStartPos.length); cm`x;[e6l
for(int i=0;i<nStartPos.length;i++) =j~Xrytn
{ &6^QFqqW`-
// output.writeLong(nPos); <nJ8%aY,
output.writeLong(fileSplitterFetch.nStartPos); ]]50c
output.writeLong(fileSplitterFetch.nEndPos); '7UIzk|
} XX'mM v
output.close(); lx&;?QQ
} \s_`ZEB
catch(IOException e){e.printStackTrace ();} I5#zo,9
catch(Exception e){e.printStackTrace ();} NU%<Ws=
} O[^u<*fi{
:\KJw
$kxP{0u
//读取保存的下载信息（文件指针位置） +J7xAyv_Oz
private void read_nPos() }o7"2hht
{ CDT3&N1'R
try{ 2py [P
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); DwIX\9
int nCount = input.readInt(); KVp3pUO
nStartPos = new long[nCount]; Iz9b5
nEndPos = new long[nCount]; z<,-:=BC"
for(int i=0;i<nStartPos.length;i++) Qw.j
{ uolEX+
nStartPos = input.readLong(); R_B`dP<"~Y
nEndPos = input.readLong(); ~c${?uf
} {J]x81}*;
input.close(); !c;BOCqa
} M1J77LfS8
catch(IOException e){e.printStackTrace ();} |`Iispn
catch(Exception e){e.printStackTrace ();} .y>G/8_i
} x"{WLZ
CQ:38l\`gd
Itv}TK eF
private void processErrorCode(int nErrorCode) ':DLv{R
{ %)sG 34
System.err.println("Error Code : " + nErrorCode); O^sOv!!RH/
} xMHu:,ND
|6!L\/}M%
tVhf1TH#
//停止文件下载 $kd9^lj#[
public void siteStop() Q3 yW#eD
{ #L9F\ <K
bStop = true; ev9ltl{
for(int i=0;i<nStartPos.length;i++) @<C<rB8R
fileSplitterFetch.splitterStop(); p #Y2v
fm$)?E_Rp
}S6"$R
} &z?:s
} _!E)a
//负责部分文件的抓取 /Bp5^(s
**FileSplitterFetch.java `R,g_{Mj
*/ #GOL%2X
package NetFox; !Hx[ `3
L<Q>:U.@\
)GR4U8<>g
import java.io.*; v6KRE3:V
import java.net.*; L<0eIw
s|IC;C|
6 B*,Mu4A
public class FileSplitterFetch extends Thread { v&Oc,W
Z^O_7I<5E
wOF";0EN
String sURL; //File URL rLp (}^
long nStartPos; //File Snippet Start Position z65Q"A
long nEndPos; //File Snippet End Position vY2^*3\<D
int nThreadID; //Thread's ID m.w.h^f$&
boolean bDownOver = false; //Downing is over U$7]*#@&
boolean bStop = false; //Stop identical ?V' zG&n@
FileAccessI fileAccessI = null; //File Access interface kR65{h"gZT
:4/37R(~l8
}N0v_Nas;v
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1)hO!%
{ tPaNhm[-q7
this.sURL = sURL; {3eg4j.Z
this.nStartPos = nStart; R?iC"s!
this.nEndPos = nEnd; T.pc3+B8N
nThreadID = id; [(*?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Y>Fh<"A|$
} 2k M;7:
Eal*){"<,?
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public void run() IIO-Jr
{ RiiwsnjC
while(nStartPos < nEndPos && !bStop) wf2v9.;X:<
{ &NH[b1NMr
u#nM_UJe
Dy|)u1?
try{ 'f-8P
URL url = new URL(sURL); uYCWsw/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x&*2R#Ai
httpConnection.setRequestProperty("User-Agent","NetFox"); og`K!d~
String sProperty = "bytes="+nStartPos+"-"; d[`vd^hI
httpConnection.setRequestProperty("RANGE",sProperty); +'{d^-( (
Utility.log(sProperty); GUC.t7!
v\dP
{'z(
InputStream input = httpConnection.getInputStream(); y&6 pc
//logResponseHead(httpConnection); (D2N_l(`<
.O6(QI*
%/w%A:y#&
byte[] b = new byte[1024]; HpIWH*
int nRead; =fK6P6'B
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) v,d'SR.
{ /wU4^8Hz
nStartPos += fileAccessI.write(b,0,nRead); M`p[ Zq
//if(nThreadID == 1) w\y)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "Pa y2
} b=XXp`h~a
qaG8:
Y|cj&<o
Utility.log("Thread " + nThreadID + " is over!"); gN.n_!
bDownOver = true; c' Q4Fzj0'
//nPos = fileAccessI.write (b,0,nRead); uU/'oZ?
} E7 P'}
catch(Exception e){e.printStackTrace ();} %r]V:d+
} J*4T|#0
} A,4Z{f83
'$5Qdaj
`J%35
//打印回应的头信息 AmB*4p5b
public void logResponseHead(HttpURLConnection con) WSbD."p<
{ c7A]\1 ~
for(int i=1;;i++) 9QHV%%
{ N#GMvU#R
String header=con.getHeaderFieldKey(i); 5#~E[dr
if(header!=null) <-"[9 w
//responseHeaders.put(header,httpConnection.getHeaderField(header)); w+gPU1|(r
Utility.log(header+" : "+con.getHeaderField(header)); ={\9-JJhE
else 4}NCdGD
break; Qrw:Bva)
} b<j*;n.
} 5M\bH'1
v]y=+* A
y wmC>`0p
public void splitterStop() <&l@ ):a
{ Y_/w}HB
bStop = true; uZa)N-=b2
} h-6x! 6pm
v+C%t!dx
0t%`jY~%
} upiYo(sN.
3;F up4!4}
C(n_*8{
/* cUr5x8<W).
**FileAccess.java _ ($U\FW
*//文件访问(定位，写) 7{p6&xXx
package NetFox; NIG* }[}P
import java.io.*; L[tq@[(IJ
Dlg9PyQ
('+C $
public class FileAccessI implements Serializable{ Q2"K!u]
S3^(L
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |LirjC4
RandomAccessFile oSavedFile; <=%=,Yk
long nPos; ?%*p!m
:kvQ3E0
V^< Zs//7
public FileAccessI() throws IOException pYh\l.@qf
{ y>0Gmr
this("",0); Jk57| )/
} T@d4NF#
O@a7MzJ
O+t'E9Fa
public FileAccessI(String sName,long nPos) throws IOException {Rq5=/b
{ G%>M@nYUE
oSavedFile = new RandomAccessFile(sName,"rw"); |xrnLdng0R
this.nPos = nPos; uOPLJ?%
oSavedFile.seek(nPos); 8aTo TA7JA
} \f'=
kV4,45r
"] ]aF1
public synchronized int write(byte[] b,int nStart,int nLen) ~0rvrDDg
{ @4Lol2
int n = -1; ,Bl_6ZaL
try{ ;0-R"c)-
oSavedFile.write(b,nStart,nLen); hbm#H7Y
n = nLen; nnCz!:9p
} iUlSRfrC$#
catch(IOException e) )H+p6<
{ W4=A.2[q
e.printStackTrace (); JhvT+"~
} tk+4noA
Wa9yyc
W!JEl|]
return n; JvYs6u
} gnlU
;&XC*R+
i<*W,D6
} meZZQ:eSl
c9Q_Qr0'
.gY=<bG/fA
/* 2:&L|;
**SiteInfoBean.java xXCsJ9]
*/ z\>ZgRi~n
package NetFox; Gm=e;X;r
^M+aQg%
0P;\ :-&p
public class SiteInfoBean { )B"E+Q'h{7
Se>v|6
h]&o)%{4
private String sSiteURL; //Site's URL _7 ^:1i~:.
private String sFilePath; //Saved File's Path <(l`zLf4p
private String sFileName; //Saved File's Name $`<-;kI
private int nSplitter; //Count of Splited Downloading File !*o{xq
{}P~nP
w`[`:H_z
public SiteInfoBean() 5Q,j+
{//nSplitter的缺省值为5 9>;CvR
//default value of nSplitter is 5 K+`deH_d
this("","","",5); } wx(P3BHD
} Mg&<W#$K
DS;.)P"
cyB2=,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) BzTzIo5
{ @>`qfy?
sSiteURL= sURL; .M0pb^M
sFilePath = sPath; bSa]={}L(
sFileName = sName; <tdsUh:?&
this.nSplitter = nSpiltter; l0eh}d
k=9k4l
2yVQqwQm
} (V0KmNCW`
t:n$9WB)
,fvhP $n
public String getSSiteURL() s1p<F,
{ n>xuef
return sSiteURL; iB+ _+A
} @>+`1C
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5>h/LE]"
public void setSSiteURL(String value) "8E=*2fcw
{ =.qPjp_Qd
sSiteURL = value; _o==
} =]o2{d
zm#%]p80f
ld#YXJ;P.k
public String getSFilePath() Lm+E?Ca
{ #wJ^:r-c`
return sFilePath; E5Lq-
} er<_;"`1
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A-u!{F
public void setSFilePath(String value) g\H~Y@'{
{ 2Hk21y\
sFilePath = value; $F6GCM3Cx
} [d=BN ,?
|}@teN^J*U
bVr`a*EM
public String getSFileName() lU.aDmy<
{ |(uo@-U
return sFileName; V-18~+F~"a
} n!U1cB{
6n H'NNS:J
w I[Hoi V
public void setSFileName(String value) Nhtc^DX
{ WLH ;{
sFileName = value; &:~9'-O
} /*Gbl
z6fY_LL
yF-`f _
public int getNSplitter() 3dgPP@7d$
{ KON^
return nSplitter; Rb0{W]opt+
} 1";s#Jq
<kazV<"
xu>grj
public void setNSplitter(int nCount) rr2^sQ;_
{ Q1!+wC
nSplitter = nCount; L;=LAQ6[
} 4^!%>V"d/
} |#Q0UM|'Q
10tTV3`IM
a[=ub256S
/* Wr8}=\/
**Utility.java dwb^z+
*/ T*k}E
package NetFox; VRg y
$<L@B|}F)
Yw\lNhoPS
public class Utility { /1eeNbd
6 kD.
NleMZ
public Utility() obGvd6\
{ $&sV.fGu
{&J OO
ITD&wg
} *P?Rucg
c`oW-K{
//线程睡眠 +y\o^w4sT
public static void sleep(int nSecond) C%#u2C2
{ W)L*zVj~
try{ pz"}o#R"x
Thread.sleep(nSecond); - x;xQ
} 2`Ihrz6
catch(Exception e) gO/\Yi
{ QE721y
e.printStackTrace (); uW4.Q_O!H
} 0XI6gPo%
} 9[[$5t`8
UDPn4q
//日志 h r6?9RJY
public static void log(String sMsg) (UZ].+)s
{ Sx1OY0)s
System.err.println(sMsg); Y4[oa?G
} k h6n(B\
&,* ILz
@0%[4
public static void log(int sMsg) *DQa6,b
{ /)sP<WPQ6
System.err.println(sMsg); F6_en z
} '_ys4hz}
} H`jnChD:M'
B/Ltb^a
i;\n\p1
/* A.(e=;0bu
**TestMethod.java p[}~Z|(
*/ Ao\Im(?
package NetFox; 8EU/}Ym
,x?Jrcx~'C
< Yc)F.:
public class TestMethod { @QE&D+NS
VFKFO9
D58RHgY[
public TestMethod() 6_K7!?YG7
{ ///xx/weblogic60b2_win.exe AB<%GzW0(
try{ yi2F#o 'K
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); U#{(*)qr
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); WwUHHm<v
SiteFileFetch fileFetch = new SiteFileFetch(bean); u1>WG?/`
fileFetch.start(); b&'YW*W
} #q5tG\gnM
catch(Exception e){e.printStackTrace ();} ndw&F'.r
fr}.#~{5Y
o ^ 08<
} 2s}G6'xE]P
MjbgAH-
h)s&Nqg1B
public static void main(String[] args) w%(D4ldp
{ 9U3.=J
new TestMethod(); <@c@`K
} g!Ui|]BI9
} # hw;aQ
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