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)); '^{:HR#i
} +55+%oGl
for(int i=0;i<nEndPos.length-1;i++) f@j)t%mh
{ _.{I1*6Y2
nEndPos = nStartPos[i+1]; qk{+Y
} @W1F4HYds
nEndPos[nEndPos.length-1] = nFileLength; 2Y7u M;8
} n9%&HDl4
} b2tUJ2p
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HM]mOmL90N
//启动子线程 RPB%6z$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {f(RYj
for(int i=0;i<nStartPos.length;i++) R<)^--n
{ 7'g{:dzS*3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :~{Nf-y0`1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q,m&XpZ
nStartPos,nEndPos,i); J#*%r)
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <2V:tj)?P
fileSplitterFetch.start(); MQY}}a-oug
} P3k@ptc-K
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ng{"W|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); u)4eu,MBT
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .N>Th/K8
nEndPos = " + nFileLength); vTl7x
// fileSplitterFetch[nPos.length-1].start(); r$cq2pkX
m<e_Z~^G
~PtIq.BY
//等待子线程结束 @2;/-,4O
//int count = 0; Tb[1\
//是否结束while循环 z[sP/{~z
boolean breakWhile = false; k d9<&.y{
fZtuP1-4
k0v&U@+-J
while(!bStop) R_zQiSwG<
{ h]jy):9L
write_nPos(); q2e=(]rKE{
Utility.sleep(500); ZnAXb S
breakWhile = true; $X_A74(
KCl85Wi'
di4>Ir~]
for(int i=0;i<nStartPos.length;i++) NVX@1}
{ 'JRYf;9c
if(!fileSplitterFetch.bDownOver) T^DJ/uhd
{ m#,AD,s
breakWhile = false; \|YIuzlO4
break; u Wxl\+_i
} =v{Vl5&>?
} ;i,3KJ[L
if(breakWhile) O%)Wo?)HM
break; '/'dg5bfV
m>9j dsqB
9SQcChG~j
//count++; 2r"J"C
//if(count>4) l2ARM3"
// siteStop(); +pY--5t
} "j/jhe6
<<Q}|$Wu
c0v6*O)
System.err.println("文件下载结束！"); $1uT`>%
} l{mC|8X
catch(Exception e){e.printStackTrace ();} B2^*Sr[
} 6qd?&.=r
e|d~&Bk0
O8k+R@
//获得文件长度 Q;?rqi ,
public long getFileSize() >/+R~ n
{ gVI{eoJ
int nFileLength = -1; 7V2xg h!W
try{ jdX*
URL url = new URL(siteInfoBean.getSSiteURL()); LaX<2]Tx:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )m$MC25
httpConnection.setRequestProperty("User-Agent","NetFox"); \A 5Na-/9
X#k:J
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int responseCode=httpConnection.getResponseCode(); Z 5 Xis"j
if(responseCode>=400) =`ECM7
{ 2&zklXuo:
processErrorCode(responseCode); V~sfR^FQ'
return -2; //-2 represent access is error UuCRQNH
} :E.T2na
r1BL?&X-
X?.tj Z,
String sHeader; dC>(UDC
@xeJ$ rlu
tz9"#=}0
for(int i=1;;i++) J^-a@'`+
{ 4hx4/5[^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); DJb9] ,=a
//Utility.log(in.readLine()); # TZ`
sHeader=httpConnection.getHeaderFieldKey(i); o]DYS,v
if(sHeader!=null) L:\>)6]Ls
{ CrB4%W:{
if(sHeader.equals("Content-Length")) g&rz*)|/
{ NwN3T]W
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Dn#^-,H
break; SQJ+C%
} Mq='|0,
} (SMk!b]}
else Xc$Zkfmms
break; e F)my
} PlR$s
} e5d STc`
catch(IOException e){e.printStackTrace ();} ,uPN\`.u8
catch(Exception e){e.printStackTrace ();} >P ~j@Lv
P)O:lYX
|W*5<2Q9
Utility.log(nFileLength); I)MRAo
{f\{{JJ]
~KczP1p
return nFileLength; 3e9UDN2
} ]app9
#nq_R
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//保存下载信息（文件指针位置） $Lz!04
private void write_nPos() (9{qT>eJg=
{ &$ fyY:<\
try{ WWTRB +1>
output = new DataOutputStream(new FileOutputStream(tmpFile)); Y+h ?HS
output.writeInt(nStartPos.length); f!F5d1N
for(int i=0;i<nStartPos.length;i++) v]#[bqB.b
{ i>KgkRZL#
// output.writeLong(nPos); n~ZZX={a
output.writeLong(fileSplitterFetch.nStartPos); <}G/x*N
output.writeLong(fileSplitterFetch.nEndPos); rv c%[HfW;
} Za]~[F
output.close(); vX_;Y#uD
} ?R_fg
catch(IOException e){e.printStackTrace ();} UrO&K]Z
catch(Exception e){e.printStackTrace ();} S`Z[MNY
} :j? MEeu
6xFchdMG{m
*z};&UsF{
//读取保存的下载信息（文件指针位置） I|wC`VgB
private void read_nPos() kt |j]:
{ `A#0If
try{ -2j[;kgt}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ' e %>Ip
int nCount = input.readInt(); ~x^Ra8A
nStartPos = new long[nCount]; .Rt~d^D@
nEndPos = new long[nCount]; UW1i%u k
for(int i=0;i<nStartPos.length;i++) -qBdcbi|x)
{ aQ-SrxmO8
nStartPos = input.readLong(); p W@Yr
nEndPos = input.readLong(); 86>@.:d
} sN K^.0
input.close(); J50n E~
} {|'NpV
catch(IOException e){e.printStackTrace ();} ;ik,6_/Y
catch(Exception e){e.printStackTrace ();} %K,cGgp^)
} bVzJOBe
2Bi?^kQ#
@?RaU4e
private void processErrorCode(int nErrorCode) }$[@*
{ -hq^';,
System.err.println("Error Code : " + nErrorCode); 7yjun|Lt}X
} .[+}nA,g%~
jz Siw z
K'B*D*w
//停止文件下载 zN9#qlfv
public void siteStop() > H&v
{ P 5.@LN
bStop = true; MS:,I?
for(int i=0;i<nStartPos.length;i++) Dp4x\97O
fileSplitterFetch.splitterStop(); uzT+,
L9oLdWa(C
6&QOC9JW+7
} x4h.WDT$
} Gqj(2.AY
//负责部分文件的抓取 4Dy1M}7
**FileSplitterFetch.java @R<z=n"
*/ /ZM xVh0
package NetFox; 9m)gp19YA
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6"NtVfui
import java.io.*; )~gIJW
import java.net.*; eeBW~_W
gW<4E=fl
5$Kd<ky
public class FileSplitterFetch extends Thread { OT(0~,.GJ
ex^9 l b
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String sURL; //File URL (BngwLVDK
long nStartPos; //File Snippet Start Position )CHXfO w
long nEndPos; //File Snippet End Position jT/P+2hMW
int nThreadID; //Thread's ID X,Rl&K\b"
boolean bDownOver = false; //Downing is over #;5Qd'
boolean bStop = false; //Stop identical dkY JO!
FileAccessI fileAccessI = null; //File Access interface j5og}Pq:
It<VjN9
bxzx@sF2l
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException HAo=t
{ $:# :"
this.sURL = sURL; w~&#:F?
this.nStartPos = nStart; +XSe;xk;rD
this.nEndPos = nEnd; aXzb]">
nThreadID = id; vxug>2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7yXJ\(6R_
} lMG+,?<uK&
5;G0$M0
}/#*opcv
public void run() &['L7
{ Bp@\p)P(
while(nStartPos < nEndPos && !bStop) j9yOkaVEg
{ |i~-,:/-Y
BsL+9lNue
R4T@ ]l&W
try{ bg/=P>2
URL url = new URL(sURL); Z9MR"!0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O}(sn
httpConnection.setRequestProperty("User-Agent","NetFox"); {p$@)b
String sProperty = "bytes="+nStartPos+"-"; gK(G1
httpConnection.setRequestProperty("RANGE",sProperty); U|{4=[
Utility.log(sProperty); 1B:5O*I!J
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z}B8&*>
InputStream input = httpConnection.getInputStream(); J}+N\V~
//logResponseHead(httpConnection); G9V2(P
?3qp?ea
j8 `7)^
byte[] b = new byte[1024]; UbGnU_}
int nRead; }_F:]lI*R
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) hW9!
{ &}0QnO_mj
nStartPos += fileAccessI.write(b,0,nRead); |@d}O8
//if(nThreadID == 1) =HJ7tele
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Nr+~3:3
} OCJt5#e~A
q@~{g[
^Sj;~
Utility.log("Thread " + nThreadID + " is over!"); Ju&FwY+
bDownOver = true; ylb)SXBf
//nPos = fileAccessI.write (b,0,nRead); u!HX`~q+A
} FCOa|IKsN
catch(Exception e){e.printStackTrace ();} %W$b2N{l
} .o5K X*
} VbMud]40F
P-$ ,
SS24@:"{
//打印回应的头信息 ^^*L;b>I
public void logResponseHead(HttpURLConnection con) i(.V`G=
{ A.@wGy4
for(int i=1;;i++) _cC1u7U9
{ xf8[&?
String header=con.getHeaderFieldKey(i); $E[M[1j
if(header!=null) AWPgrv/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]=ZPSLuEm%
Utility.log(header+" : "+con.getHeaderField(header)); 'h7x@[|
else if*~cPnN
break; aMxj{*v7
} Q[aF"5h%
} yPe9KN_
,fTC}>s4
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public void splitterStop() mPqKk
{ :-<30LS$
bStop = true; nqx0#_K-E
} 63_#*6Pv28
jUl_ToX
5''k|B>
} cH$(*k9%M
wq,&0P-v
7cWeB5e?O
/* o8H\l\(
**FileAccess.java u"%D;
*//文件访问(定位，写) t#8QyN
package NetFox; ZMr[:,Jp
import java.io.*; EkRx/
1Y;.fZE
?Q+*[YEJ5
public class FileAccessI implements Serializable{ KKb7dZbt<
zY@0R`{@p
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 nk_X_y
RandomAccessFile oSavedFile; GA` bWl
long nPos; r..f$FF)\
n[r1h=?j3
ujN~l_4
public FileAccessI() throws IOException {dP6fr1z
{ $)c[FR~a
this("",0); z C$F@
} t9*e"QH
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[{R>'~
public FileAccessI(String sName,long nPos) throws IOException Z]WX 7d
{ __s'/6u
oSavedFile = new RandomAccessFile(sName,"rw"); |,S]EHIy
this.nPos = nPos; nUVk;0at
oSavedFile.seek(nPos); w-$iKtb.
} (x@J@ GP*
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public synchronized int write(byte[] b,int nStart,int nLen) i `p1e5$
{ 7lAJ 0
int n = -1; W"pHR sf
try{ W/u(9
oSavedFile.write(b,nStart,nLen); Nu3IYS5&
n = nLen; <n2'm
} Anpp`>}N
catch(IOException e) 6I=xjgwvf
{ . XbDb
e.printStackTrace (); fF>hca>
} i92Z`jiR
]B8iQr-!
8''1H<f
return n; $I/ !vV
} c+7I
"'+C%
uHbbPtk
} zFipuG02
=jpRv<X|,
Pg`+Q^^6S
/* pFiE2V_aS
**SiteInfoBean.java kB5y}v.3 S
*/ "\rO}(gC;`
package NetFox; Er8F_,M+
`mYp?NjR_
{|j-e{*
public class SiteInfoBean { BILZ XMf
'Z,7{U1P
_Gb7n5p
private String sSiteURL; //Site's URL g2}aEfp!H
private String sFilePath; //Saved File's Path S:xs[b.ZZ
private String sFileName; //Saved File's Name k\/es1jOEh
private int nSplitter; //Count of Splited Downloading File PR(KDwsT&l
+!`$(
p14$XV
public SiteInfoBean() ;[g~h |{6
{//nSplitter的缺省值为5 CR't
//default value of nSplitter is 5 $ntC{a>&
this("","","",5); 2\O!vp>|-
} _U*1D*kLI[
I{H!KrM!
j\Fbi3H
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -sle7k
{ V1G5Kph
sSiteURL= sURL; (U.VCSn
sFilePath = sPath; |\"%Dy[m
sFileName = sName; Zw/??Tq b
this.nSplitter = nSpiltter; /z)8k4
j *N^.2
m{lS-DlRg
} (f#{<^gd
1OqVNp%K
~+RrL,t#
public String getSSiteURL() xBw ua;
{ t)(>E'X x
return sSiteURL; SokU9n!
} H66~!J0;a
ms+gq
: 9zEne4
public void setSSiteURL(String value) k9\n='OI
{ f|yq~3x)
sSiteURL = value; 1'k,P;s
} =)Goip
::/vDUDc
y>g`R^^
public String getSFilePath() x^pHP|<3`
{ g$#JdN
return sFilePath; (Fk&~/SP
} V0F1X s`
_.,"`U; H
~%: TE}
public void setSFilePath(String value) +]VW[$W
{ :?#wWF.
sFilePath = value; 0J= $ A
} BT5~MYBl
kh>i#9Ie
'}P$hP_d
public String getSFileName() R_:-Z.
{ h#|Ac>fz
return sFileName; sNC~S%[
} VOp+6ho<
ve(@=MJ
e#tWQM3
public void setSFileName(String value) y#lg)nB
{ MPsm)jqX
sFileName = value; jSvo-
} "fd'~e$S#
7{=+Va5
!/e8x;_
public int getNSplitter() x&FBh!5H
{ Lez]{%+.`[
return nSplitter; KVpQ,x&q~
} 8RVeKnpXTV
t;[?Q\
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public void setNSplitter(int nCount) -kzg(+sm
{ 3HX-lg`0
nSplitter = nCount; hXn@vK6
} T@N)BfkB
} qNbgN{4
Ymg,NkiP0
i$'#7U
/* ogE|8`Tq^
**Utility.java Mj |"+(
*/ :DBJ2n
package NetFox; %TQ5#{Y
{=E,.%8
!f8]gTzN
public class Utility { 4({Wipd
ew8Manx
LBhDP5qF
public Utility() HwZ@T &_4
{ N*>&XJ#
IeE6?!,)
5'3H$%dC
} T4"*w
x*F_XE1#M
//线程睡眠 jX91=78d
public static void sleep(int nSecond) M4}zRr([.5
{ &uu69)u
try{ f1/if:~6
Thread.sleep(nSecond); At8^yF
} 6b=7{nLF
catch(Exception e) >zcp(M98
{ ,6^V)F
e.printStackTrace (); e&XJK*Wf
} %0Ke4c
} T9Pu V
? `#
//日志 WLN;LT
public static void log(String sMsg) zB)wYKwZ
{ ( ESmP
System.err.println(sMsg); \EeK<)4:
} 7.1FRxS
~C;gEE-
EcmyY,w
public static void log(int sMsg) 1cPjgBxv#
{ 'tzN.p1O
System.err.println(sMsg); Q!}LtR$
} hk+"c^g:j<
} si>gYO
{DGnh1
*[wj )
/* L@LT*M
**TestMethod.java 83YQ c
*/ U~[ tp1Z)
package NetFox; wE09%
zRF+D+
$8Y|&P
public class TestMethod { wg 6
_,]@xFCOH
3!KEk?I]
public TestMethod() }Fgp*x-G
{ ///xx/weblogic60b2_win.exe &$E.rgtg
try{ )u(Dqu\t
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *v9 {f?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Eg|C
SiteFileFetch fileFetch = new SiteFileFetch(bean); ZuQ\Pyx
fileFetch.start(); W&Gt^5
} &Kc'g H
catch(Exception e){e.printStackTrace ();} u}IQ)Ma
5QJFNE
BpZ17"\z
} k8ej.
p3z%Y$!Tm
N"o+;yR
public static void main(String[] args) @)p?!3{"
{ O_/|Wx
new TestMethod(); ~l>2NY
} ,*'aH z
} #`{L_n$c
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