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)); 2n]Br
} _Jc[`2Uv_c
for(int i=0;i<nEndPos.length-1;i++) Re{vO&.
{ +KV`+zic+
nEndPos = nStartPos[i+1]; %(,Kj ~0
} XP"lqyAi
nEndPos[nEndPos.length-1] = nFileLength; =r=YV-D.
} <T[wZ[l
} [kIiKLX
ZzNp#FrX"
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//启动子线程 B`xrdtW
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Fcc\hV;
for(int i=0;i<nStartPos.length;i++) A&OU;j]
{ fWKI~/eUY|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;x*_h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~5[#c27E9
nStartPos,nEndPos,i); 9H9 P'lx9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LwV4p6A
fileSplitterFetch.start(); tO$/|B74Bz
} h|tdK;)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F(J6 XnQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }]ak6'|[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", O9#8%p% )
nEndPos = " + nFileLength); _s/5oRHA
// fileSplitterFetch[nPos.length-1].start(); v&p|9C@
HrH-e=j
82.::J'e
//等待子线程结束 Lj"@JF;c
//int count = 0; t%$>
//是否结束while循环 X\:;A{
boolean breakWhile = false; r5kKNyJ
x w8 e
owDp?Sy}E
while(!bStop) bhqBFiuhH
{ |kPjjVGF{
write_nPos(); ALVHKL2
Utility.sleep(500); b!C\J
breakWhile = true; K!c "g,S
SW!lSIk
y3^<rff3Gc
for(int i=0;i<nStartPos.length;i++) a\60QlAk~
{ /a}F;^
if(!fileSplitterFetch.bDownOver) [ZC{eg+D
{ [&e|:1
breakWhile = false; A}Q6DHh26
break; c]SXcA;Pmv
} F7!g+LPc<
} AI{Tw>hZ
if(breakWhile) d<{>&
break; wldv^n hM
EDQKbTaPt
HjCWsQM
//count++; u^HC1r|%
//if(count>4) LhN?j5XqM
// siteStop(); BG>fLp
} wKxw|Fpn
~m:oJ+:O
[Dr'
System.err.println("文件下载结束！"); 7Gwn,&)
} 05o)Q &`
catch(Exception e){e.printStackTrace ();} ,%)O/{p_
} ENZjRf4
Q=YIAGK
H(L.k;B
//获得文件长度 kYbqb?
public long getFileSize() " pg5w
{ 5&59IA%S
int nFileLength = -1; E}?n^Zf
try{ R;mA2:W)x
URL url = new URL(siteInfoBean.getSSiteURL()); W|X=R?*ZK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J,iS<lV_
httpConnection.setRequestProperty("User-Agent","NetFox"); 6,wi81F,}
?3[Gh9g`
p**Sd[|
int responseCode=httpConnection.getResponseCode(); {KQ-QKxxS
if(responseCode>=400) >:o$h2
{ {}.M(nPtv;
processErrorCode(responseCode); 7+!FZo{?
return -2; //-2 represent access is error dC'8orFG+
} P2-^j)
Dq07Z^#'
F,dPmR
String sHeader; h^QLvOuR
6zyxGJ(
]A?(OA
for(int i=1;;i++) ]|m?pt
{ +56N}MAs
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -!@]z2uU
//Utility.log(in.readLine()); p!oO}gE
sHeader=httpConnection.getHeaderFieldKey(i); 0P_=Oy"l-
if(sHeader!=null) /penB[1i
{ 7)RDu,fx
if(sHeader.equals("Content-Length")) \wZ 4enm
{ ~,^pya
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #%9t-
break; Rb/|ae
} ^X]rFY1
} u0Q6+U
else b=L4A,w~a
break; Z=+Tw!wR>
} @23?II$=@
} "?*B2*|}`
catch(IOException e){e.printStackTrace ();} ,=a+;D]'
catch(Exception e){e.printStackTrace ();} ]F{F+r
#]rfKHW9
G;ihm$Cad
Utility.log(nFileLength); $~3?nib"j
O*SJx.
FOyANN'
return nFileLength; R$Rub/b6
} ;NoiH&
7|@FN7]5NF
K' ?`'7
//保存下载信息（文件指针位置） _^Z v[P
private void write_nPos() W{$J)iQ
{ iFOa9!_0n
try{ awU!3)B
output = new DataOutputStream(new FileOutputStream(tmpFile)); (^HU|
output.writeInt(nStartPos.length); ~XeWN^l(Ov
for(int i=0;i<nStartPos.length;i++) <)$e*HrI
{ XQ'$J_hC
// output.writeLong(nPos); ,Gi%D3lA
output.writeLong(fileSplitterFetch.nStartPos); \? n<UsI
output.writeLong(fileSplitterFetch.nEndPos); u5.zckV
} Leu6kPk
output.close(); Hg~8Td**
} Dz3~cuVb
catch(IOException e){e.printStackTrace ();} ~hxW3e
catch(Exception e){e.printStackTrace ();} G_QV'zQ
} $jg~a
5_\1f|,
3,"G!0 y.
//读取保存的下载信息（文件指针位置） F! [Gj%~I
private void read_nPos() h1~/zM/`
{ LVaJyI@/>
try{ {zI>"%$u
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); tXCgRU
int nCount = input.readInt(); 2Rqpok4
nStartPos = new long[nCount]; yJ:rry
nEndPos = new long[nCount]; !lL~#l:F
for(int i=0;i<nStartPos.length;i++) }U^iVq*
{ 6{w'q&LYcE
nStartPos = input.readLong(); I.gF38Mx
nEndPos = input.readLong(); i'B$Xr
} sB*!Nf^y
input.close(); C';Dc4j
} ~bqw!rz
catch(IOException e){e.printStackTrace ();} ,`8:@<e
catch(Exception e){e.printStackTrace ();} *EPJeblAV
} G|I}x/X"Q7
<M,<|Y*)
%KPQ|^WE
private void processErrorCode(int nErrorCode) x9o(q`N
{ @dn&M9Z
System.err.println("Error Code : " + nErrorCode); $Ji;zR4,
} u}?|d8$h\
B2:GGZ|jS
OD~yIV
//停止文件下载 ` Nv1sA#C
public void siteStop() !TN)6e7`
{ +Mb}70^
bStop = true; mYqLqezAA
for(int i=0;i<nStartPos.length;i++) 5S ) N&%
fileSplitterFetch.splitterStop(); T3Sz<K$E
~ %Ij5PD
QJ%N80
} ba)hWtenH
} n0)y|B#
//负责部分文件的抓取 s)+] pxV0-
**FileSplitterFetch.java (_Th4'(@Y
*/ RJ-J/NhWyI
package NetFox; sT,*<^
^[6#Kw&E
(/S6b
import java.io.*; 5^{I}Q
import java.net.*; h(i_'P?
#@F
x=N0H
public class FileSplitterFetch extends Thread { KvjH\;78
Q6p75$SVq
9R:?vk4
String sURL; //File URL As??_=>4
long nStartPos; //File Snippet Start Position p::`1
long nEndPos; //File Snippet End Position [;#^h/5E
int nThreadID; //Thread's ID bV:MOj^
boolean bDownOver = false; //Downing is over L?(m5u~b
boolean bStop = false; //Stop identical v?o("I[ C
FileAccessI fileAccessI = null; //File Access interface N.vkM`Z
!N/?b^y
aW#^@||B
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException UoJMOw[
{ o}Zl/&(
this.sURL = sURL; \,G19o}`Es
this.nStartPos = nStart; &D`$YUl@
this.nEndPos = nEnd; s5ILl wr
nThreadID = id; 1#x@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 lgC^32y
} n*hRlL
MNX-D0`g
_:Ov-HIR
public void run() 0Hr)h{!F"
{ 9abn6S(XpJ
while(nStartPos < nEndPos && !bStop) LufZ,
{ OQ _wsAA
3ZqtIQY`
<7oZV^nd *
try{ 8u Z4[
URL url = new URL(sURL); C7!=LiK}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;_1>nXh
httpConnection.setRequestProperty("User-Agent","NetFox"); o2^?D`Jr
String sProperty = "bytes="+nStartPos+"-"; tp b(.`G
httpConnection.setRequestProperty("RANGE",sProperty); c#pVN](?
Utility.log(sProperty); gWy2E;"a
aIE\B4w
eD N%p
InputStream input = httpConnection.getInputStream(); GEAVc9V
//logResponseHead(httpConnection); NTSKmCvQG
HgRfMiC
]2xoeNF/W{
byte[] b = new byte[1024]; {N0ky=ud
int nRead; cWa>rUsF
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) DO? bJ01
{ =e]Wt/AQ
nStartPos += fileAccessI.write(b,0,nRead); ]K%D$x{+\
//if(nThreadID == 1) Ay\!ohIS3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nHB`<B
} 4\Cb4jq%/
RH<C:!F^
[oS.B\Vc
Utility.log("Thread " + nThreadID + " is over!"); dUpOg{I.x
bDownOver = true; Alb5#tm:m
//nPos = fileAccessI.write (b,0,nRead); #e;\Eap
} Uf-`g>
catch(Exception e){e.printStackTrace ();} (9D,Ukw
} cWL7gv\|
} jz$83TB-
W$Zc;KRz$0
"zN]gz=OV>
//打印回应的头信息 [es-&X07<
public void logResponseHead(HttpURLConnection con) s)|l-I
{ agW#"9]WM
for(int i=1;;i++) ;hp?wb
{ rDWqJ<8
String header=con.getHeaderFieldKey(i); `'<&<P
if(header!=null) [+v}V ,jb
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a0x/?)DO
Utility.log(header+" : "+con.getHeaderField(header)); ~0@+8%^>;
else %O3 r>o=
break; @Y2&v956
} IK^jzx
} O}_Z"y
ZN?UkFnE
tvG/oe .1'
public void splitterStop() e#$ZOK)`
{ ocT.2/~d
bStop = true; (eAh8^)
} D2}nJFR ]
,*@6NK,.
,, G6L{&Z
} +Ss|4O}'
`Z0#IeX=
fX2PteA0qX
/* i;$'haK<
**FileAccess.java Xpd^^
*//文件访问(定位，写) ii@O&g
package NetFox; DOm5azO!>
import java.io.*; TBYRY)~f
]OOL4=b
[UHDN:y
public class FileAccessI implements Serializable{ xFY;aK
v+|N7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 nUvxO `2
RandomAccessFile oSavedFile; b%<i&YY#
long nPos; (U |[C*
UC34AKm
Py8<db%
public FileAccessI() throws IOException |0mVK`
{ X|7Y|0o
this("",0); 5E/z.5 q
} ivbuS-f=r
Whq@>pX8
ymBevL
public FileAccessI(String sName,long nPos) throws IOException ``A=p<W
{ rsR0V+(W
oSavedFile = new RandomAccessFile(sName,"rw"); ?Q]{d'g(sx
this.nPos = nPos; [S/]Vk|4
oSavedFile.seek(nPos); ]64mSB
} 1v4(
e/m,PE
DT@6Q.
public synchronized int write(byte[] b,int nStart,int nLen) \@4_l?M
{ 5"5D(
int n = -1; ( {H5k''
try{ \gL H_$}
oSavedFile.write(b,nStart,nLen); zZ|Si
n = nLen; qlSc[nEk
} @l^=&53T
catch(IOException e) RTNUHz;{L
{ MX?K3=j @>
e.printStackTrace (); xaWmwsym
} {@9y%lmrh
$@t-Oor;
lu(<(t,Lbs
return n; +xwz.:::
} OCF\*Sx
9 I> 3p4]
PqIGc
} Gv}*Tw$
RR><so%
Te~"\`omJ3
/* dx@#6Fhy
**SiteInfoBean.java !Ljs9 =UF
*/ su(y*187A
package NetFox; I-i)D
EW1L!3K
-3X#$k8
public class SiteInfoBean { 7Rj!vj/
@<\f[Znto
~ @Ib:M
private String sSiteURL; //Site's URL jcN84AaRFI
private String sFilePath; //Saved File's Path f 5_n2
private String sFileName; //Saved File's Name J /'woc
private int nSplitter; //Count of Splited Downloading File <FMW%4
%$I\\qq>{
y%=\E
public SiteInfoBean() Fm{Ri=X<:
{//nSplitter的缺省值为5 ~o%|#-S
//default value of nSplitter is 5 6!/e_a
this("","","",5); h/`OG>./
} Oe^3YOR#j{
Vy{=Y(cpF2
`ItMn&P
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J& +s
{ kYz)h
sSiteURL= sURL; X\hD4r"
sFilePath = sPath; '+Dn~8Y+9
sFileName = sName; FJv=5L
this.nSplitter = nSpiltter; &7T0nB/)
0kpRvdEr-
42:\1B#[
} ? 8S0
B>t$Z5Q^X
O:RPH{D
public String getSSiteURL() G[r_|-^S
{ OAR1u}
return sSiteURL; _+%-WFS|
} xg'z_W
D<#+ R"
`.Y["f 1B
public void setSSiteURL(String value) Mvrc[s+o
{ F^IYx~:
sSiteURL = value; C!B2.:ja
} -Uq I=#
+e%9P%[+
u1ggLH!U
public String getSFilePath() e1S |&W8
{ vX)JJ|g
return sFilePath; 4/S4bk*8
} 7h<Q{X<A
6~0S%Hz
Y1H8+a5@
public void setSFilePath(String value) 5l2Ph4(
{ D.j'n-yw
sFilePath = value; - P1OD)B
} 8Cs)_bj#!
q0.+F4
^P~%^?(
public String getSFileName() U'UV=:/-
{ }/[tB
return sFileName; ={W;8BUV%^
} "dXRUg"
4!d&Zc>C4
Q{UR3U'Q
public void setSFileName(String value) Zb8Ty~.\P
{ F5wCl2I
sFileName = value; _$NFeqLww
} =ILs[p
V? w;YTg
8uM>UpX
public int getNSplitter() :f ybH)*
{ ,<zGvksk
return nSplitter; )~T)$TS
} _jR%o1Y}
dfiA- h
A$WE:<^
public void setNSplitter(int nCount) Ji :2P*
{ VD;Ot<%
nSplitter = nCount; V2,54YE
} U voX\
} GX&BUP\
=_\5h=`Yx
x:88E78
/* ixw3Z D(>+
**Utility.java &xgMqv2/
*/ s-}|_g.Pt
package NetFox; s&iM.[k
~jH@3\ ?-
D*o_IrG_(
public class Utility { Q`4=
,icgne1j
'+?AaR&p?
public Utility() ?!U=S=8
{ }BKEz[G(
2S&e!d-
m beM/
} 4{(uw
X,IjM&o"Y
//线程睡眠 sHyhR:
public static void sleep(int nSecond) ^rfY9qMJr8
{ [!]a' T#x
try{ L$cNxz0$
Thread.sleep(nSecond); #M$[C d I$
} Jor>YB`X
catch(Exception e) -ZlBg~E
{ zIi|z}WJ
e.printStackTrace (); TUIj-HSe
} *&q\)\(3w
} WM.JoQ
jA$g0>
//日志 s:7^R-"
public static void log(String sMsg) QzPq^
{ U[*VNJSp
System.err.println(sMsg); F^7qLvh
} K~H)XJFF
K:Wxx"
i6?,2\K
public static void log(int sMsg) %%`Nq&'
{ jGl8y!aM
System.err.println(sMsg); swYlp
} kQ7$,K#
} WjW+EF8(
0^az<!!O#
E0'+]"B
/* = I,O+^
**TestMethod.java VLC<ju!
*/ B]L5K~d
package NetFox; U&yXs'3a&
.+MJ' bW
<+o-{{E[
public class TestMethod { jl;_lcO
rL3<r
FB9PIsFS
public TestMethod() /vll*}}
{ ///xx/weblogic60b2_win.exe 1 0lvhzU
try{ L6./b;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'MRvH lCM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); I|9(*tq)
SiteFileFetch fileFetch = new SiteFileFetch(bean); HS XS%v/Y
fileFetch.start(); f]`#BE)V
} n0F.Um
catch(Exception e){e.printStackTrace ();} FRd!UqMXY
(+68s9XS7
<cNXe4(
} WSi`)@.XO
J(JsfU4
G3'>KMa.
public static void main(String[] args) ?YWfoH4mS
{ ,(dg]7
new TestMethod(); bO 2>ced
} ) DXN|<A
} g@wF2=
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