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)); %}SrL*
} > PRFWO
for(int i=0;i<nEndPos.length-1;i++) ;#W2|'HD
{ p_gm3Q
nEndPos = nStartPos[i+1]; AUG#_HE]k
} c<:-T
nEndPos[nEndPos.length-1] = nFileLength; t6"%3#s
} r= `Jn6@
} ^1I19q
|.: q
RB7tmJc
//启动子线程 q_[o"wq/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]nn98y+
for(int i=0;i<nStartPos.length;i++) !Iy_UfW
{ V(I8=rVH
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $Vg>I>i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), EU/C@B2*Dl
nStartPos,nEndPos,i); C_}]`[
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nV|EQs4(
fileSplitterFetch.start(); mp1@|*Sn
} Uiw2oi&_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HAdg/3Hw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?=sDM& '
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :%=Xm
nEndPos = " + nFileLength); @Md/Q~>
// fileSplitterFetch[nPos.length-1].start(); yLvDMPj
<`=j^LU
UERLtSQ
//等待子线程结束 .5_2zat0H
//int count = 0; 2`K=Hby
//是否结束while循环 gh]cXuph
boolean breakWhile = false; ZPLm]I\]
AofKw
SwGx?U
while(!bStop) g wRZ%.Cn
{ S&wMrQ
write_nPos(); W' VslZG
Utility.sleep(500); 6Pl<'3&
breakWhile = true; /hR&8 `\\
,?%Zc$\LW
9s q
for(int i=0;i<nStartPos.length;i++) Rh{f5-
{ kS);xA8s]
if(!fileSplitterFetch.bDownOver) lukB8
{ eu-*?]&Di
breakWhile = false; Dw.J2>uj
break; -`h)$&,
} H/ HMm{4
} EI%89i`3^
if(breakWhile) rglXs
break; gPI ?C76
K($Npuu]
6<QQ@5_
//count++; @Cyvf5|bL
//if(count>4) 4xje$/_d
// siteStop(); *w\W/Y
} $Ds2>G4c
*L^,|
77f9(~ZnT
System.err.println("文件下载结束！"); .|70;
} i[3'ec3
catch(Exception e){e.printStackTrace ();} [}=B8#Jl-C
} IOmfF[
K+3=tk]W9u
+I|vzz`ZVr
//获得文件长度 2HA:"v8
public long getFileSize() hL{KRRf>
{ tS=(}2Q
int nFileLength = -1; ;*Et[}3
try{ "<1{9
URL url = new URL(siteInfoBean.getSSiteURL()); /(*q}R3Kfo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }&J q}j
httpConnection.setRequestProperty("User-Agent","NetFox"); :crW9+
0'C1YvF
dR,fXQm
int responseCode=httpConnection.getResponseCode(); 29.h91
if(responseCode>=400) @RKryY)
{ zRr*7G
processErrorCode(responseCode); #)O65GI
return -2; //-2 represent access is error aX'*pK/-
} sDlO#
%P|/A+Mg"
Z@!+v19^
String sHeader; mz0X3
/nA{#HY
YNF k
for(int i=1;;i++) BW4J>{
{ htF] W|z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ggR.4&<
//Utility.log(in.readLine()); gjDHo$
sHeader=httpConnection.getHeaderFieldKey(i); HIZe0%WPw
if(sHeader!=null) Kn1a>fLaJ_
{ E ~<JC"]
if(sHeader.equals("Content-Length")) rjYJs*#
{ 0x@ mZ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); OQJ6e:BGt
break; q@8*Xa>
} jQB9j
} Tyx_/pJT
else H**Xu;/5@
break; s.C_Zf~3
} &V/MmmT
} *z8\Lnv~k
catch(IOException e){e.printStackTrace ();} k5pN
catch(Exception e){e.printStackTrace ();} %*}(}~
0\P1; ak%
Ad_hKO
Utility.log(nFileLength); %Q|Atgp
zK@@p+n_#.
HG^'I+Yn
return nFileLength; vXje^>_6
} `b$.%S8uj=
!+v$)3u9
2BwO!Y[
//保存下载信息（文件指针位置） ISvpQ 3{)s
private void write_nPos() fNFY$:4X
{ }pkzH'$HJ
try{ wf<M)Rs|
output = new DataOutputStream(new FileOutputStream(tmpFile)); }BP;1y6-r
output.writeInt(nStartPos.length); KbeC"mi
for(int i=0;i<nStartPos.length;i++) Qvhl4-XjZa
{ H/M@t\$Dc
// output.writeLong(nPos); cbTm'}R(G
output.writeLong(fileSplitterFetch.nStartPos); PdWx|y{%
output.writeLong(fileSplitterFetch.nEndPos); 5=ryDrx
} >4CbwwMA
output.close(); _oeS Uzq.
} gg2(5FPP
catch(IOException e){e.printStackTrace ();} w\O;!1iU
catch(Exception e){e.printStackTrace ();} 4o[{>gW
} sfl<qD+?
=dN@Sa/
N;`n@9BF
//读取保存的下载信息（文件指针位置） 8Zd]wYO
private void read_nPos() =T7.~W
{ Y.p;1"
try{ oEpFuWp%A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _H@DLhH|=
int nCount = input.readInt(); GZIa4A
nStartPos = new long[nCount]; sFRQe]zCcP
nEndPos = new long[nCount]; u>vL/nI
for(int i=0;i<nStartPos.length;i++) H<+TR6k<
{ Xsa].
nStartPos = input.readLong(); cw <l{A
nEndPos = input.readLong(); 4o5t#qP5$S
} Jln:`!#fDf
input.close(); j#4kY R{
} o ^uA">GH
catch(IOException e){e.printStackTrace ();} 1?l1:}^L
catch(Exception e){e.printStackTrace ();} U]rRQ d/:;
} do'GlU oMC
'LDQgC*%
\s\?l(ooq"
private void processErrorCode(int nErrorCode) 4#Jg9o
{ O;3>sLgc
System.err.println("Error Code : " + nErrorCode); p6S8VA
} =7UsVn#o
^S; -fYW2
cFXp
//停止文件下载 [dz _R
public void siteStop() $%f&a3#
{ ~a2}(]
bStop = true; 5[0?g@aO
for(int i=0;i<nStartPos.length;i++) w,D+j74e$
fileSplitterFetch.splitterStop(); j1<Yg,_.p
CAf6:^0
&UFZS94@r
} ~wdGd+ez
} #AY&BWS$
//负责部分文件的抓取 gjlx~.0d
**FileSplitterFetch.java !5!<C,U
*/ {{!-Gr
package NetFox; Q+{n-? :
%(Icz?
);YDtGip J
import java.io.*; 1xvu<|F
import java.net.*; r.U`Kh]K
Q,Eo mt
|w3M7;~eF
public class FileSplitterFetch extends Thread { gRzxLf`K
VIbq:U
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String sURL; //File URL /gas2k==^
long nStartPos; //File Snippet Start Position \OoWo
long nEndPos; //File Snippet End Position %a7$QF]
int nThreadID; //Thread's ID izR"+v
boolean bDownOver = false; //Downing is over ~}Pfu
boolean bStop = false; //Stop identical % ]U
FileAccessI fileAccessI = null; //File Access interface vP,n(reM
7xR\kL.,
e'<)V_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "J1 4C9u
{ "r2 r
this.sURL = sURL; 2fS:- 8N
this.nStartPos = nStart; vih9KBT
this.nEndPos = nEnd; W%w~ah|/]
nThreadID = id; 0*v2y*2V
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Gq P5Kx+=
} $:^td/p J
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;AG()NjOO:
public void run() 19] E 5'AI
{ W@esITr
while(nStartPos < nEndPos && !bStop) +w~oH=
{ Uw:"n]G]D?
0+8e,
G+m }MOQP7
try{ MqMQtU9w
URL url = new URL(sURL); z(~_AN M4,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E*lxVua
httpConnection.setRequestProperty("User-Agent","NetFox"); moE2G?R
String sProperty = "bytes="+nStartPos+"-"; eJX#@`K
httpConnection.setRequestProperty("RANGE",sProperty); !'O@2{?B
Utility.log(sProperty); VtohL+
1E$|~
uw8f ~:LT
InputStream input = httpConnection.getInputStream(); !`r$"}g
//logResponseHead(httpConnection); )M^ gT}M
]_$[8#kg
w2'5#`m
byte[] b = new byte[1024]; 5-A\9UC*@
int nRead; &nK<:^n
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) qJw_
{ y_[vr:s5pG
nStartPos += fileAccessI.write(b,0,nRead); I`#JwMU;m
//if(nThreadID == 1) J~- 4C)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AOx[
} "Yy n/
t`QENXA}
Xnh8e
Utility.log("Thread " + nThreadID + " is over!"); ##ANrG l
bDownOver = true; i@'dH3-kO
//nPos = fileAccessI.write (b,0,nRead); S]{oPc[7
} K> e7pu
catch(Exception e){e.printStackTrace ();} ;n},"&
} sR8"3b<qA
} 3gf1ownC
g\AY|;T
M3Kfd
//打印回应的头信息 b`_Q8 J
public void logResponseHead(HttpURLConnection con) j+YJbL v
{ ,z?':TZ
for(int i=1;;i++) A2Tw<&Tw(
{ ,u!sjx
String header=con.getHeaderFieldKey(i); aQ~s`^D
if(header!=null) D)Dr__x
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wA.\i
Utility.log(header+" : "+con.getHeaderField(header)); MO]&bHH7;
else nj4/#W
break; dqAw5[qMJ
} eDB;cN
} w*Ihk)
"7`<~>9t.
.|=\z9_7S8
public void splitterStop() &.ACd+Cd
{ <-0]i_4sK
bStop = true; azU"G(6y?+
} Y^]rMK/;
O H7FkR
=w^M{W.w
} S[QrS7
E)3NxmM#
)}ROLe
/* (iGTACoF
**FileAccess.java B?wq=DoG
*//文件访问(定位，写) 2+O'9F_v
package NetFox; Wez5N
import java.io.*; O'~+_ykTl
hzC>~Ub5
Vz[C=_m
public class FileAccessI implements Serializable{ U<-D(J
CH/rp4NeSy
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^W@5TkkBQq
RandomAccessFile oSavedFile; "h ^Z
long nPos; aN=B]{!
Er[A X.3
J-4:H gx
public FileAccessI() throws IOException 'W#D(l9nI
{ 1nOCQ\$l
this("",0); bN88ua}k{
} |Ds=)S" K
A(N4N
(9h`3#
public FileAccessI(String sName,long nPos) throws IOException &~w}_Fjk
{ BluVmM3Vj
oSavedFile = new RandomAccessFile(sName,"rw"); 9{uO1O\
this.nPos = nPos; P }uOJVQ_
oSavedFile.seek(nPos); $wU\Js`/S]
} u2[w#
%K QQ,{ b
d5l UGRg
public synchronized int write(byte[] b,int nStart,int nLen) QdC<Sk!G
{ a}uSm/S
int n = -1; {BHO/q3
try{ PxE3K-S)G
oSavedFile.write(b,nStart,nLen); \|ao`MMaD<
n = nLen; v.ui!|c
} bu"!jHPB
catch(IOException e) a'z7(8$$
{ &VcV$8k
e.printStackTrace (); 1i] ^{;]
} FCn_^l)EA
Tb-F]lg$
.}*"Nv
return n; wvPk:1wD5
} i 3SHg\~Z
;S*}WqP,
m#F`] {
} 9)=ctoZ'
ei{eTp4HpV
f V(J|
/* 8KNZ](Dj
**SiteInfoBean.java cs'{5!i]
*/ 4'Zp-k?5`
package NetFox; d`6 'Z
V470C@
+t;7tQDVB
public class SiteInfoBean { Xs?o{]Fe
"wHFN>5B
~3 bPIg7D
private String sSiteURL; //Site's URL E+JqWR5
private String sFilePath; //Saved File's Path :/Qq@]O>
private String sFileName; //Saved File's Name ]$_NyAoBb
private int nSplitter; //Count of Splited Downloading File kSh( u
?F;8Pa/
!v0LBe4
public SiteInfoBean() /FJu)H..U
{//nSplitter的缺省值为5 C>w|a
//default value of nSplitter is 5 = 9]~yt
this("","","",5); )>- =R5ZV
} \'bzt"f$j
O0y_Lm\
09Cez\0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0K2`-mL
{ *D3/@S$B
sSiteURL= sURL; tNX|U:Y*
sFilePath = sPath; >e"#'K0?\
sFileName = sName; jalg5`PU0
this.nSplitter = nSpiltter; @|%2f@h
t`mV\)fa
Wiu"k%Qsh
} U`m54f@U
}AH] th
?1eK#Z.
public String getSSiteURL() 7Rt9od< )!
{ >oe]$r
return sSiteURL; J9[r|`gJ(
} :[!j?)%>
abLnI =W`
e@OX_t_
public void setSSiteURL(String value) {8%a5DiM
{ w*JGUk
sSiteURL = value; $ DSZO!pB
} Q)[C?obd v
> "=>3
J6aef^>
public String getSFilePath() & 9 ?\b7
{ w)Qp?k d
return sFilePath; 2('HvH]k
} Hg$lXtn]
w G<yBI0
46&/gehr
public void setSFilePath(String value) NPe%F+X
{ <HVt V9R
sFilePath = value; EJNU761
} >s?S+W[L
:zF,A,)
'y3!fN=h
public String getSFileName() .xWC{}7[
{ OH(waKq2I
return sFileName; +&2%+[nBZ
} =$Nq
e;}7G
Ak"m 85B
public void setSFileName(String value) KNIn:K^/
{ 5,6"&vU,
sFileName = value; [ ~&/s:Vvo
} ah+iZ}E%
wx0j(:B]
X*@dj_,
public int getNSplitter() 9c :cw
{ d,n 'n
return nSplitter; &@Be2!%'9K
} Y\?"WGL)p
>e[i5
(jl D+Y_
public void setNSplitter(int nCount) 6MMOf\
{ BeoDKdAwY
nSplitter = nCount; JHTSUq
} Hn+~5@.
} !NvI:C_4|
l3I:Q^x@
r:ptQo`1-
/* >_"an~Ss
**Utility.java $6iX
*/ 2)HuZda
package NetFox; D!-g&HBTC
DwE[D]7o
T!WT;A
public class Utility { AogVF
!\.pq 2
jQ^|3#L\
public Utility() R3&Iu=g
{ wHMX=N1/
DjQFi
'=8d?aeF
} MXNFlP
uH- l%17
//线程睡眠 LR.<&m%~.
public static void sleep(int nSecond) Fgh_9S9J
{ A1>OY^p3%
try{ Oso#+
Thread.sleep(nSecond); .jT#:_
} c?[I?ytl
catch(Exception e) MH9q ;?.J
{ ;LSANr&
e.printStackTrace (); 1+{{EOZ4
} %oa-WmWm
} *Y7u'v
W_(j3pV?Ml
//日志 EGU 0)<
public static void log(String sMsg) X296tA>C`
{ hxd`OG<gF
System.err.println(sMsg); 94.DHZqh
} DJ [#5h5
BdblLUGK#
;d"F%M y
public static void log(int sMsg) Y}|X|!0x
{ " h~Zu
System.err.println(sMsg); CiLg]va
} `1{ZqRFQ
} F]]]y5t
/,&<6c-Q@W
=O_4|7Zl
/* `l){!rg8IC
**TestMethod.java KD7dye
*/ Tg)|or/%
package NetFox; O6a<`]F
wX5tp1 ?1J
ipgC RHE
public class TestMethod { j8{i#;s!"
qqr?!vem6
f:|1_j
public TestMethod() 6J6BF%
{ ///xx/weblogic60b2_win.exe oiT[de\S
try{ j2.|ln"!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {Y=WW7:Qx
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); YPK(be_|I
SiteFileFetch fileFetch = new SiteFileFetch(bean); =llvuUd\n
fileFetch.start(); pF:$ ko
} 9gEwh<
catch(Exception e){e.printStackTrace ();} ?;+1)>{
)E@.!Ut4o
JNYFD8J~
} >#~& -3
>j(_[z|v3
cr?Q[8%t1
public static void main(String[] args) (\hx` Yh=>
{ 7#ibN!
new TestMethod(); q#ClnG*
} %D}kD6=
} aweV#j(y
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