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)); jN\u}!\O
} Cf 2@x
for(int i=0;i<nEndPos.length-1;i++) i"WYcF|
{ *'?7OL
nEndPos = nStartPos[i+1]; %2?+:R5.
} xT%`"eM}
nEndPos[nEndPos.length-1] = nFileLength; n t}7|h|
} p;O%W@n"
} mQj=-\p
l4OrlS/5
>]\I:T
//启动子线程 c.ow4~>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; i[o 2(d,
for(int i=0;i<nStartPos.length;i++) s6!6Oqh
{ !+eH8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vADiW~^Q^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #c^V%
nStartPos,nEndPos,i); *m~-8_ >;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,`@pi@<"#
fileSplitterFetch.start(); 7?$?Yu
} j/FLEsU!R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ={qcDgn~C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); eU[g@Pq:Y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [3Pp NCY
nEndPos = " + nFileLength); [nTI\17iA
// fileSplitterFetch[nPos.length-1].start(); GJ+^t
K3T.l#d'L
6l#x1o;
//等待子线程结束 ,NSf
//int count = 0; .Pb-{!$Ni
//是否结束while循环 :DD<0
boolean breakWhile = false; Lo%n{*if
WYw#mSp
lW+mH=
while(!bStop) -(qRC0V
{ Zh"m;l/]
write_nPos(); [#PE'i4
Utility.sleep(500); szI7I$Qb
breakWhile = true; M/zO|-j&
,_2-Op
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for(int i=0;i<nStartPos.length;i++) Yj%]|E-
{ a.Ho>(V/4
if(!fileSplitterFetch.bDownOver) ^*K=wE}AG
{ r|Ui1f5
breakWhile = false; . %RM8
break; b)LT[>f
} i0vm00oT
} D(!^$9e9b
if(breakWhile) p4`1^}f&Ie
break; G]^[i6PQs
w!.@64-
yvAO"43
//count++; "mlQ z4D)5
//if(count>4) @60D@Y
// siteStop(); 2w 2Bc+#o
} d#k(>+%=Q
t]/eCsR
Nk|cU;?+
System.err.println("文件下载结束！"); j(;^XO Y#
} ,,H"?VO
catch(Exception e){e.printStackTrace ();} :|S zD4Ag
} }>A q<1%
hAGHb+:
YH&=cI@
//获得文件长度 z/@_?01T=
public long getFileSize() 8Zv``t61
{ RBX<>*
int nFileLength = -1; U7r8FLl
try{ nbi7rcT
URL url = new URL(siteInfoBean.getSSiteURL()); {o=?@$6C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NGx3f3 9
httpConnection.setRequestProperty("User-Agent","NetFox"); *ByHTd
*rxr:y#Ve
5/meH[R\M
int responseCode=httpConnection.getResponseCode(); HA6tGZP*L
if(responseCode>=400) i"8mrWb
{ T]#V
processErrorCode(responseCode); &V"oJ}M/a
return -2; //-2 represent access is error !X>u.}?g
} e+ xQ\LH
6Rc=!_v^
aeqz~z2~8s
String sHeader; VYvfx
K_7pr~D]@r
@/2Kfr
for(int i=1;;i++) gQ1obT"|
{ SN{z)q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0-. d{P
//Utility.log(in.readLine()); r*X,]\V0x
sHeader=httpConnection.getHeaderFieldKey(i); y<)TYr
if(sHeader!=null) vOQ%f?%G\
{ @Nu2 :~JO
if(sHeader.equals("Content-Length")) 91-bz^=xO
{ Dk1& <} I
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5!-TLwl`j\
break; g: i5%1
} 9}573M
} zWsr|= [
else i\R0+O{
break; OM*_%UF
} ua\t5M5
} kaG/8G(
catch(IOException e){e.printStackTrace ();} 'B@`gA
catch(Exception e){e.printStackTrace ();} m[hL GD'Fi
%!aU{E|@_
oA1_W).wJ
Utility.log(nFileLength); FG?Mc'r&
la!]Y-s)'4
8@3K, [Mo
return nFileLength; sI ,!+
} $Y/9SD
0;Z|:\P\=
<izQ]\kL
//保存下载信息（文件指针位置） /{M<FVXK+|
private void write_nPos() YQVo7"`%
{ \kADh?phV
try{ sNf& "C!;
output = new DataOutputStream(new FileOutputStream(tmpFile)); fXD+
output.writeInt(nStartPos.length); KA3U W
for(int i=0;i<nStartPos.length;i++) d} >Po%r:
{ RLF&-[mr3
// output.writeLong(nPos); GES}o9?#
output.writeLong(fileSplitterFetch.nStartPos); rxY|&!f
output.writeLong(fileSplitterFetch.nEndPos); _Q V=3UWP
} Di9RRHn&q
output.close(); U82a]i0
} #Z&/w.D2
catch(IOException e){e.printStackTrace ();} 1? >P3C
catch(Exception e){e.printStackTrace ();} SzULy >e
} ou,[0B3n0
/:dLqyQ_V
=BJLj0=N
//读取保存的下载信息（文件指针位置） e`*}?N4d
private void read_nPos() ]#/nn),Z
{ t,/ G
try{ )"?4d[ 5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); SV7;B?e%Y
int nCount = input.readInt(); (?FH`<
nStartPos = new long[nCount]; [%W'd9`>
nEndPos = new long[nCount]; 86&M Zdv6
for(int i=0;i<nStartPos.length;i++) KK|w30\f
{ 1wSAwpz
nStartPos = input.readLong(); 2TK \pfD
nEndPos = input.readLong(); %?~'A59
} &@=Jm /5
input.close(); }=R]<`Sj.j
} \#sD`O
catch(IOException e){e.printStackTrace ();} %nA})nA7=
catch(Exception e){e.printStackTrace ();} q0sf\|'<}
} dFg>uo
tV}!_
h~dQ5%
private void processErrorCode(int nErrorCode) sXLW';Fz
{ >.:+|Br`
System.err.println("Error Code : " + nErrorCode); n@p]v*
} =SDex.ZK]
7h' C"rH
^2+Ex+
//停止文件下载 UQVL)-Z
public void siteStop() awLvLkQb{
{ a~o<>H
bStop = true; XF`2*:7
for(int i=0;i<nStartPos.length;i++) P^Hgm
fileSplitterFetch.splitterStop(); +Y;P*U}Qg[
Dy08.Sss
b,!C8rJ
} 'nmGHorp
} DE13x*2
//负责部分文件的抓取 I8#2+$Be+@
**FileSplitterFetch.java e=amh
*/ t}t(fJHY`
package NetFox; _~FfG!H ^X
?0qVyK_1
s 6Wp"V(
import java.io.*; BR|!ya+_2
import java.net.*; S"bN9?;#u
nz 10/nw
R'c*CLaiE
public class FileSplitterFetch extends Thread { W'G|sk
d_[H|H9i6
1(' wg!
String sURL; //File URL %-hSa~20
long nStartPos; //File Snippet Start Position uWS]l[Ga
long nEndPos; //File Snippet End Position )W\)37=.
int nThreadID; //Thread's ID I| TNo-!$
boolean bDownOver = false; //Downing is over $<*) 5|6
boolean bStop = false; //Stop identical B4s$| i{D
FileAccessI fileAccessI = null; //File Access interface jCd]ENl+_
]3r}>/2(
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException y4\X~5kU
{ iSfRJ:_&6
this.sURL = sURL; S!K<kn`E3
this.nStartPos = nStart; U1\EwBK8*T
this.nEndPos = nEnd; 3Tr,waV
nThreadID = id; .G/Rh92
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vG|!d+
} z']6C9m}
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KGt:
public void run() KpN]9d
{ XG#?fr}L
while(nStartPos < nEndPos && !bStop) hB[bth
{ vNi;)"&*
^} {r@F
*F$@!ByV
try{ TE`5i~R*
URL url = new URL(sURL); Va!G4_OT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^[hAj>7_8$
httpConnection.setRequestProperty("User-Agent","NetFox"); =OufafZb
String sProperty = "bytes="+nStartPos+"-"; 7cc^n\c?Y
httpConnection.setRequestProperty("RANGE",sProperty); -jQ*r$iRE
Utility.log(sProperty); hqRC:p#9
HDm]njF%qQ
2gWR2 H@
InputStream input = httpConnection.getInputStream(); wd:Yy
//logResponseHead(httpConnection); 9qX$
!ooi.Oz*Tu
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byte[] b = new byte[1024]; XtCIUC{r,
int nRead; lpT&v;$`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &M-vKc"d
{ sRB=<E*_
nStartPos += fileAccessI.write(b,0,nRead); # epP~J_f
//if(nThreadID == 1) wv~:^v'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @Y0ZW't
} xMbgBx4+
.!1[I{KU
3ynkf77cn
Utility.log("Thread " + nThreadID + " is over!"); |bk9<i ?
bDownOver = true; ~[=<Os
//nPos = fileAccessI.write (b,0,nRead); D5gj*/"
} `%YMUBaI
catch(Exception e){e.printStackTrace ();} |s3;`Nxu7
} m|NZ093d
} /xX7:U b
f@}>:x
'Agw~ &$
//打印回应的头信息 %g:Q?
public void logResponseHead(HttpURLConnection con) >H+tZV
{ (wj:Gc
for(int i=1;;i++) eA N{BPN[
{ d==0 @`
String header=con.getHeaderFieldKey(i); 2n.HmS
if(header!=null) R*GBxJaw
//responseHeaders.put(header,httpConnection.getHeaderField(header)); H*]Vs=1
Utility.log(header+" : "+con.getHeaderField(header)); 5V 2ZAYV
else ?j&hG|W9<z
break; <zCWLj3
} Cm;cmPPl
} y)zZ:lyIq
?I]AE&4'
iM!Ya!
public void splitterStop() b}TvQ+W]2
{ h6k" D4o\
bStop = true; DN:| s+Lz
} {Q>OZm\+
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a!R*O3
} L9jT:2F
]9_gbQ
NL]_;\ h
/* K/9Jx(I,qL
**FileAccess.java b |:Y3_>
*//文件访问(定位，写) "{8j!+]4i
package NetFox; JuZkE9C,${
import java.io.*; Mbc&))A
[~Ky{:@)[
@QTw9,pS
public class FileAccessI implements Serializable{ 1G]D:9-?
.I_atv
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7"eK<qJ
RandomAccessFile oSavedFile; t]I9[5Pq\
long nPos; kqX=3Zo
S ,F[74K
fTXip)n!r
public FileAccessI() throws IOException P;"moluE;
{ Cu`
this("",0); ![Qi+xyc
} xHt7/8wF
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{m!5IR
public FileAccessI(String sName,long nPos) throws IOException 0{vT`e'
{ +a39 !j 1_
oSavedFile = new RandomAccessFile(sName,"rw"); 3IRur,|'
this.nPos = nPos; OxDqLX
oSavedFile.seek(nPos); e6MBy\*n
} 6):1U
N!ihj:,
(Yz[SK=U}
public synchronized int write(byte[] b,int nStart,int nLen) a0hBF4+6
{ Sm<*TH!\n_
int n = -1; e1g3a1tnWl
try{ /4O))}TX
oSavedFile.write(b,nStart,nLen); WowT!0$
n = nLen; i&m_G5u88
} 2.WI".&y=
catch(IOException e) %16Lo<DPm
{ w71YA#cg
e.printStackTrace (); tAq0Z)
} bN-!&Td
,K[e?(RP
inh:b .,B
return n; TC-Vzk G|
} qkKl;Z?Y:
Iuz_u2"C
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} vyDxX
^'[QCwY~
rJGh3%
/* M6&=-
**SiteInfoBean.java 0U~$u
*/ +YZo-tE
package NetFox; |dQz(z&6{5
!-tw
6!>p<p"Ns
public class SiteInfoBean { XfE0P(sE
$ (;:4
|'-aR@xJ
private String sSiteURL; //Site's URL !#pc@(rE
private String sFilePath; //Saved File's Path )T"Aji-hy
private String sFileName; //Saved File's Name nQQHm6N
private int nSplitter; //Count of Splited Downloading File ~-Kx^3(#
2b7-=/[6
<=p>0L
public SiteInfoBean() hYpxkco"4'
{//nSplitter的缺省值为5 QOEi.b8r
//default value of nSplitter is 5 `bBkPH}M
this("","","",5); C W#:'
} Hy4;i^Ik <
3}FZg w .
>=97~a+.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ke8g tbm
{ -XXsob}/8
sSiteURL= sURL; KO=$Hr?f;
sFilePath = sPath; G+N1#0,q
sFileName = sName; 1iY4|j;ahV
this.nSplitter = nSpiltter; ~\(c;J*Ir
[ne51F5_
}0pp"[JU
} /%g9g_rt#
\{`^Q+<
qK7:[\T|?T
public String getSSiteURL() w^Y/J4 I0
{ <L8|Wz
return sSiteURL; EtzSaB*|
} Xgd-^
-_nQn
W]/J]O6
public void setSSiteURL(String value) msgR"T3'
{ o3hgkoF
sSiteURL = value; ;Tr,BfV|Bf
} 5e.aTW;U
l#enbQ`-~
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public String getSFilePath() />mK.FT
{ "'bl)^+?,
return sFilePath; ,2$<Pt;
} <4.Exha;=
!DOyOTR&3
j~>{P=_}
public void setSFilePath(String value) ^Zz^h@+
{ lS,Jo/T@
sFilePath = value; 2c]"*Pb
} }(8>&
g>h/|bw4
2|^@=.4\
public String getSFileName() pDlrK&;\z
{ y@l&B+2ks
return sFileName; :pdX
} V5(_7b#z``
FA*$ dwp
-y|J_;EG
public void setSFileName(String value) )XN%pn
{ -B#1+rUW
sFileName = value; U.,S.WP+d
} =_pSfKR;
_cQ '3@
is8i_FoD,n
public int getNSplitter() `{:Nt#7
{ Ht;Rz*}
return nSplitter; xx!8cvD4?
} SPE)db3
v^@)&,
YA$YT8iMe
public void setNSplitter(int nCount) ,5v'hG
{ =xm7i#1
nSplitter = nCount; *"WP*A\1
} |:5O|m '
} h,R Isq;`
J-tqEK*
Mu>
/* :41Y
**Utility.java Wq_#46P-
*/ yUb$EMo\
package NetFox; 9Foo8e
8r^~`rL
/5^"n4/M
public class Utility { -LF0%G
wYtL1D(
<qD/ #$
public Utility() %vjLw`
{ vkdU6CZO
rixP[`!]x
2c>eMfa
} tGGv 2TCEy
P+iZ5S\kL=
//线程睡眠 I^iJ^Z]vx
public static void sleep(int nSecond) OhmKjY/}
{ c@RMy$RTF
try{ UUy%:t
Thread.sleep(nSecond); ,?Pn-aC+
} *I;,|Jjk
catch(Exception e) 0be1aY;m&
{ z?$F2+f&
e.printStackTrace (); K31G>k@
} P-9[,3Zd
} yT Pi/=G
Pl_4;q!$
//日志 )ndcBwQc"
public static void log(String sMsg) k0IW,z%
{ laX(?{_
System.err.println(sMsg); H=E`4E#k
} iOpMU
o:kiIZ]
$:M*$r^u
public static void log(int sMsg) Ov1$7 r@
{ n}9vAvC
System.err.println(sMsg); J(*qOGBD
} $mvcqn;
} qd*3| O^
aEr<(x!|"
*<k8H5z8]
/* D"o}XTH
**TestMethod.java f}q4~NPn-
*/ Zw+VcZz3
package NetFox; [Nb0&:$ay
\u@4eBAV
7Iu^l4=2
public class TestMethod { UpL1C~&
,i>u>YNZ
Az4+([
public TestMethod() 7'wt/9
{ ///xx/weblogic60b2_win.exe `>CHE'_
try{ {~.~ b+v
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $o rN>M42
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); F"2v5F@
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5wM*(H^c[
fileFetch.start(); 8A/;a{
} / fBi9=}+
catch(Exception e){e.printStackTrace ();} hwF9LD~^
c$?(zt;
j^ L"l;m
} f49pIcAq
i^j1i
Q 6djfEN>
public static void main(String[] args) Il(p!l<Xz#
{ ]h4^3
new TestMethod(); KL:x!GsV5e
} nn>1OO
} %lVc7L2]
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