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)); 2?\L#=<F
} </Ry4x^A
for(int i=0;i<nEndPos.length-1;i++) g(F?qP_K
{ >O}J*4A>+#
nEndPos = nStartPos[i+1]; B;xGTl@8
} %Dm:|><V$b
nEndPos[nEndPos.length-1] = nFileLength; /S&8%fb
} Z1M{5E
} $#d.@JWi
L=5Fvm
t+Hx&_pMj
//启动子线程 %%f(R7n
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; dSIZsapH
for(int i=0;i<nStartPos.length;i++) wv_<be[?*
{ n ^_B0Rkv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z^yhSbE{5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), .?p\=C@C+
nStartPos,nEndPos,i); rty&\u@}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $|r p5D6
fileSplitterFetch.start(); 9aZ^m$tAt
} }uk]1M2=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lF.yQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !0 -[}vvU
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mY,t]#^m7
nEndPos = " + nFileLength); #~`]eM5`J
// fileSplitterFetch[nPos.length-1].start(); keL!;q|r-)
?tFsSU
sn?YD'>k
//等待子线程结束 6$6Qk !%
//int count = 0; R3Ka^l8R|
//是否结束while循环 <.B^\X$
boolean breakWhile = false; B[nkE+s
7__?1n~{
[*AWCV
while(!bStop) Tx\g5rk
{ `Aa*}1
write_nPos(); m5rJY/
Utility.sleep(500); 7O.{g
breakWhile = true; hpOUz%
('VHL!
KL\]1YX
for(int i=0;i<nStartPos.length;i++) $(U}#[Vie
{ njN]0l{p
if(!fileSplitterFetch.bDownOver) %1jApCJ
{ 9 ?~Y
breakWhile = false; -*r]9f6x
break; <m3or
} '{(/C?T
} {#'M3z=
if(breakWhile) ,Y3wXmG
break; 1-bQ ( -
|ZnRr
XTOZ]H*^
//count++; .A2u7*h&
//if(count>4) R1=ir# U|D
// siteStop(); {BlKVsQ
} @lnM%
]9}T)Df'
6Y[|xu:N8Y
System.err.println("文件下载结束！"); q4rDAQyPO
} ^,M&PP6
catch(Exception e){e.printStackTrace ();} ,$qqHSd1M
} MlM2(/ok
5h4E>LB.B
6b8@6;&LI
//获得文件长度 3]9twfF 'J
public long getFileSize() FTg4i\Wp
{ VI(;8
int nFileLength = -1; 2iM8V
try{ %VCfcM}5I
URL url = new URL(siteInfoBean.getSSiteURL()); _2,eS[wP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P;dp>jL
httpConnection.setRequestProperty("User-Agent","NetFox"); @-ma_0cZQ
joN}N}U
$qx&\@O
int responseCode=httpConnection.getResponseCode(); !j3V'XU#Zn
if(responseCode>=400) f2#9E+IQ
{ s\`Vr;R:|
processErrorCode(responseCode); /~LXY<-(
return -2; //-2 represent access is error N&0MA
} `37GVo4
i~IQlyGr.
Qjj:r~l
String sHeader; Y"uFlHN&i
#c0 dZ
@x@w<e%
for(int i=1;;i++) >q&Q4E0
{ #&1Y!kbdd
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); X'&$wQ6,K
//Utility.log(in.readLine()); !j(KbAhWZ
sHeader=httpConnection.getHeaderFieldKey(i); bw7!MAXd
if(sHeader!=null) ~EU[?
{ t#y
if(sHeader.equals("Content-Length")) xX'Uq_Jv
{ ndm19M8Y|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I_yIVw;
break; r<oI4px
} 6bg+U`&g
} 0;)6ZU
else |zu>G9m
break; K)qbd~<\
} sQ^>.yG
} Y\T*8\h_[
catch(IOException e){e.printStackTrace ();} rI}E2J
catch(Exception e){e.printStackTrace ();} ~zz|U!TG
ru`;cXa,
k~Pm.@,3o
Utility.log(nFileLength); !v2,lH
hh"0z]
);h\0w>3
return nFileLength; Z"gllpDr$
} oQDOwM,
JLAg-j2
#{0DpSzE5
//保存下载信息（文件指针位置） c 3@SgfKmk
private void write_nPos() D,eJR(5I
{ Snt=Hil`
try{ H/V%DO
output = new DataOutputStream(new FileOutputStream(tmpFile)); uz4mHyS6
output.writeInt(nStartPos.length); 4C/8hsn
for(int i=0;i<nStartPos.length;i++) q rbF@{
{ hkgPC-
// output.writeLong(nPos); +&\TdvNI4
output.writeLong(fileSplitterFetch.nStartPos); l@*/1O)v
output.writeLong(fileSplitterFetch.nEndPos); J'O`3!Oy/
} Kc udWW]
output.close(); eq/5$b(
} vP}K(' (
catch(IOException e){e.printStackTrace ();} l``1^&K
catch(Exception e){e.printStackTrace ();} :,q3?l6
} Q]xW}5 /
QBsDO].J<
w#mnGD
//读取保存的下载信息（文件指针位置） ,.FTw,<
private void read_nPos() qd|*vE
{ <(p1 j0_Q
try{ 3R#<9O
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !P Gow
int nCount = input.readInt(); <Awx:lw.
nStartPos = new long[nCount]; 0K3FH&.%
nEndPos = new long[nCount]; ($(1KE
for(int i=0;i<nStartPos.length;i++) *vAOUqX`x
{ GvzPT2E!
nStartPos = input.readLong(); w78Ius,
nEndPos = input.readLong(); lIjHd#q-C
} Aq'%a)Y2
input.close(); =cC]8Pz?
} c0G/irK
catch(IOException e){e.printStackTrace ();} deTbvl
catch(Exception e){e.printStackTrace ();} RO.(k!J .
} vWkKNB
"(efd~.]
wCt+{Y3T
private void processErrorCode(int nErrorCode) 4\OELU
{ Ok`U*j
System.err.println("Error Code : " + nErrorCode); Zc4hjg
} "}HQ)54&
_Mt:^H}Sy
)ql?}
//停止文件下载 #6H<JB
public void siteStop() pV("NJj!
{ J$I1*~I4v
bStop = true; `u>BtAx8
for(int i=0;i<nStartPos.length;i++) @J<B^_+Se
fileSplitterFetch.splitterStop(); #8z\i2I
dY-a,ch"8p
>Au<y,Tw
} >A,WXzAK}S
} 3N*Shzusbt
//负责部分文件的抓取 G>RYQ{O
**FileSplitterFetch.java C(0Iv[~y/
*/ 17i^|&J6}:
package NetFox; *Yr-:s9J9
xY'g7<})$
,xh9,EpBk
import java.io.*; &vF"I'V
import java.net.*; )(L&+DDy
<@vE3v;
;ZqFrHI M`
public class FileSplitterFetch extends Thread { AX,Db%`l,
tJu<#hX
wKeqR$
String sURL; //File URL yY| .
long nStartPos; //File Snippet Start Position 3QHZC0AY
long nEndPos; //File Snippet End Position {PVu3W
int nThreadID; //Thread's ID ,){0y%c#y
boolean bDownOver = false; //Downing is over $Tur"_`I;
boolean bStop = false; //Stop identical .E}});l
FileAccessI fileAccessI = null; //File Access interface aXJe"IT.u
Y@4vQm+
XP`kf]9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException qJ/C*Wqic
{ 8Cqs@<r4Od
this.sURL = sURL; "|G,P-5G"
this.nStartPos = nStart; ^]DWrmy
this.nEndPos = nEnd; @Hf}PBb
nThreadID = id; k`AJ$\=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Td F<
} %xfy\of+Nk
j&Aq^aI
`/AzX *`
public void run() 72,iRH
{ y%,BDyK
while(nStartPos < nEndPos && !bStop) :9YQX(l8
{ -0X> y
0@Ijk(|
|d3agfS[n
try{ 0&\Aw'21
URL url = new URL(sURL); (>K$gAQH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L&N"&\K2U
httpConnection.setRequestProperty("User-Agent","NetFox"); qC4-J)8Wk
String sProperty = "bytes="+nStartPos+"-"; jwq"B$ap
httpConnection.setRequestProperty("RANGE",sProperty); HxMsH5;
Utility.log(sProperty); 0l=}v%D
4r. W:}4:
19.cf3Dh
InputStream input = httpConnection.getInputStream(); $;CC lzw
//logResponseHead(httpConnection); kUUq9me&o
#~x5}8
*[5
byte[] b = new byte[1024]; Ax0,7,8y
int nRead; W*<]`U_.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <C$<(Dw5
{ g,:Nzb
nStartPos += fileAccessI.write(b,0,nRead); AVr!e
//if(nThreadID == 1) jVINc=o
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K*Jtyy}r
} K|G$s
ja;5:=8A5
Vi#im`@
Utility.log("Thread " + nThreadID + " is over!"); >>$|,Q-.
bDownOver = true; [tzSr=,Cg
//nPos = fileAccessI.write (b,0,nRead); {K9E% ,w
} c Vn+~m_%
catch(Exception e){e.printStackTrace ();} V)2_T!e%*
} =b7&(x
} dNQSbp
vy@Lu cB
pD#"8h
//打印回应的头信息 doc
public void logResponseHead(HttpURLConnection con) XX-T",
{ q&E5[/VK:
for(int i=1;;i++) fqb$_>3Ol
{ 5G!U'.gr
String header=con.getHeaderFieldKey(i); f4S@lyYF
if(header!=null) {{3H\ rR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wP/9z(US
Utility.log(header+" : "+con.getHeaderField(header)); RC(D=6+[C
else 4QFOO sNp
break; 1[l>D1F?
} IBkH+j
} HzV+g/8>A
y.:-
$-]setdY
public void splitterStop() ^,K.)s
{ 8uxFXQ
bStop = true; 5{q/z^]
} WdqK/s<jM
RuNH (>Eb
ennz/'
} t4_K>Mj+d
(u&yb!`
:WIf$P?X
/* WWcm(q=
**FileAccess.java AtlR!IEUb
*//文件访问(定位，写) !2|`aa
package NetFox; kA<r:/
import java.io.*; ?ev G=S4>
pMp9O/u%
+~Lzsh"
public class FileAccessI implements Serializable{ }pnFJ
xqWrW)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,?<h] !aQ
RandomAccessFile oSavedFile; m]d6@"Z.
long nPos; +Nbk\%
!otq X-
DD 5EHJR
public FileAccessI() throws IOException 1IQOl
{ 7(8
this("",0); Jf<yTAm
} "!Oh#Vf
DUKmwKM"k
yr9A0F0
public FileAccessI(String sName,long nPos) throws IOException |C6(0fgWd
{ pZ~>l=-
oSavedFile = new RandomAccessFile(sName,"rw"); V1nZ M
this.nPos = nPos; q4GW=@eD
oSavedFile.seek(nPos); T0v@mXBQ
} ilp;@O6
3ZL7N$N}7
tW.>D;8
public synchronized int write(byte[] b,int nStart,int nLen) d)1sP0Z_@
{ +'j*WVE%5
int n = -1; OO\biYh o
try{ p:<gFZb
oSavedFile.write(b,nStart,nLen); JJ9e{~0I
n = nLen; <Mn7`i
} &iiK ZZ`_o
catch(IOException e) !BQ ELB$0
{ K: o|kd
e.printStackTrace (); ;=VK_3"
} ^$+f3Z'
|@L &yg,x
0tm_}L$g=b
return n; 7cmr *y
} ]7S7CVDk4
CDwIq>0j
aQ&8fteFR
} lDPRn~[#\
hW!@$Ph
#D LT-G0
/* h[je_^5
**SiteInfoBean.java aU.0dsq
*/ zNr_W[
package NetFox; fFZ`rPb
h/0-Mrk;e
2mG&@E
public class SiteInfoBean { 1Q&WoJLfR
.)^3t~
w[YkTv
private String sSiteURL; //Site's URL ?9zoQ[
private String sFilePath; //Saved File's Path %<J(lC9,C
private String sFileName; //Saved File's Name ?V5Pt s
private int nSplitter; //Count of Splited Downloading File !/Bw,y ri<
Pvg
7Ysy\gZ&wp
public SiteInfoBean() }Cmj(k`~
{//nSplitter的缺省值为5 !: EW21m
//default value of nSplitter is 5 bV )PT`-,
this("","","",5); ^=izqh5S
} 4-d99|mv
,LW(mdIe(
{GX &)c4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Z\*5:a]
{ )kL`&+#>
sSiteURL= sURL; c5iormb"#
sFilePath = sPath; ,p*ntj{
sFileName = sName; ^Z-.[Y
this.nSplitter = nSpiltter; /UaNYv/
fUp|3bBE
9&XV}I,~?|
} e"o6C\c
,Y g5X
XC7Ty'#"KX
public String getSSiteURL() ^T}}4I_Y
{ +;:aG6q+
return sSiteURL; u"#6_-0y
} J:g<RZZ1
$/<"Si&(
"5o;z@(
public void setSSiteURL(String value) RFZU}.*K$
{ Pghva*&
sSiteURL = value; AT%* ~tr
} As6)_8w
je- ,S>U
@Hspg^
public String getSFilePath() F= _uNq
{ Cz=A{<^g
return sFilePath; VW{aUgajO
} kO..~@aY
kwDh|K
^Hz
public void setSFilePath(String value) h\D_
{ zt)p`kdD
sFilePath = value; u@=+#q~/P
} so?pA@O
S{^6iR
Nl=m'4@`
public String getSFileName() ]=?X*,'
{ PS_3Oq)
return sFileName; gtaV6sD
} {2}tPT[a(
zqHpT^B?
pIID=8RJ.
public void setSFileName(String value) gZ`32fB%
{ A6?qIy
sFileName = value; R/ALR
} nV!2Dfd
pY{; Yn&t
O3^98n2
public int getNSplitter() #Acon7Rp
{ ysSjc
return nSplitter; 6)=](VmNL`
} IZ4W_NN
r.^0!(d
s jL*I
public void setNSplitter(int nCount) e={k.y}x}
{ eVqM=%Q
nSplitter = nCount; $l#v/(uFa
} bn0"M+7)f
} A5CdLwk
[n!$D(|"!V
?8Hn{3X
/* mV6#!_"
**Utility.java 52>[d3I3
*/ ?ada>"~GR_
package NetFox; aqcFY8b '
>|l;*Kw,/P
Pk$}%;@v
public class Utility { ry$tK"v/
k-{yu8*';
f:_=5e +
public Utility() $cRcap
{ ^c/mj9M#C
(3e;"'k
AyE%0KmraK
} ?"()>PJx
L@7Qs6G2u
//线程睡眠 6P0y-%[Gk
public static void sleep(int nSecond) ~Y\QGuT
{ "nVK< Vd
try{ i?ZA x4D
Thread.sleep(nSecond); J$1j-\KS
} =YWT|%^uX
catch(Exception e) n"(7dl?
{ l<u{6o
e.printStackTrace (); 4uFIpS|rq
} #0}Ok98P
} )J;ny!^2
6a7vlo
//日志 [m~b[ZwES
public static void log(String sMsg) `Ac:f5a
{ BqQ] x'AF
System.err.println(sMsg); ||R0U@F,
} /rqqC(1
qpoquWZ
- o4@#p>>
public static void log(int sMsg) [}{w
{ I!61 K
System.err.println(sMsg); )X7e$<SU*
} 4S'[\ZJO
} E3y6c)<
U?^OD
lco~X DI
/* ^SEc./$
**TestMethod.java Tj Mb>w9
*/ DG3[^B
package NetFox; pfR"s:#
+eU`H[iu
?2/uSG|
public class TestMethod { *nLIXnm
Ee2c5C!|C
N_DT7
public TestMethod() 80B>L
{ ///xx/weblogic60b2_win.exe r\M9_s8
try{ Tg ?x3?kw
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); f CcD&<%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 'Kbl3fUF
SiteFileFetch fileFetch = new SiteFileFetch(bean); QIU,!w-3X
fileFetch.start(); Is.WZYa
} ;4#D,zlO^
catch(Exception e){e.printStackTrace ();} LE=k
e@]Wh)
vO@s$qi
} -kj< 1~YW
^TFs;|..
KMK`F{
public static void main(String[] args) yTBS=+X
{ 2eP;[o
new TestMethod(); l{WjDed
} D'[Uc6
} pwX C
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