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)); \>/AF<2"
} odeO(zuU
for(int i=0;i<nEndPos.length-1;i++) ~8Ef`zL
{ ,E(M<n|.
nEndPos = nStartPos[i+1]; wGz_IL.D
} w@N)Pu
nEndPos[nEndPos.length-1] = nFileLength; $iy(+}
} 6>d3*
} '~6l 6wi
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+I~U8v-
//启动子线程 tN)Vpb\J
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; '#r^W2
for(int i=0;i<nStartPos.length;i++) HBa6Y&)<
{ G)5Uiu:^X
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /X\:3P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H,fVF837
nStartPos,nEndPos,i); 8/9YR(H3H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j1@PfKh
fileSplitterFetch.start(); FZ% WD@=
} <dY{@Cgw=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :)Nk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); t1l4mdp
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Gm\jboef]
nEndPos = " + nFileLength); zt )WX9
// fileSplitterFetch[nPos.length-1].start(); vnsMh
NjA\*M9
4,6?sTuX
//等待子线程结束 xO 1uHaL
//int count = 0; Ac,bf 8C
//是否结束while循环 $)O\i^T
boolean breakWhile = false; XOY\NMo
41XXL$
b@1";+(27
while(!bStop) P6ugbq[x#e
{ SQ`ec95',
write_nPos(); 6}mSA@4&
Utility.sleep(500); 6<Zk%[7t
breakWhile = true; B{_-k
|VX0o2
H`U>ZJ.
for(int i=0;i<nStartPos.length;i++) Su`] ku'
{ Fc"+L+h@W
if(!fileSplitterFetch.bDownOver) <C7/b#4>\
{ m3b?f B
breakWhile = false; nqujT8
break; 3rv~r0
} 3n TpL#
} `XwKCI
if(breakWhile) +?[iB"F
break; v.]W{~PI2V
htqC~B{1E
.`N&,&H
//count++; I* JSb9r
//if(count>4) q}7(w$&
// siteStop(); fL R.2vJ
} ez*O'U
cU=/X{&Om
[IuF0$w=dj
System.err.println("文件下载结束！"); |G>Lud
} =^3B&qQNq
catch(Exception e){e.printStackTrace ();} WPNvZg9*c
} T;JA.=I
,Z]4`9c
:j!N7c{
//获得文件长度 +QFY.>KH
public long getFileSize() d[Rs
{ rexy*Xv`2p
int nFileLength = -1; GI*2*m!u
try{ 2Y{r2m|o
URL url = new URL(siteInfoBean.getSSiteURL()); _M}}H3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |/p2DU2
httpConnection.setRequestProperty("User-Agent","NetFox"); /H[!v:U
q1o)l
\wo'XF3:
int responseCode=httpConnection.getResponseCode(); IDv|i.q3
if(responseCode>=400) r*s)T`T}}
{ #_OrS/H
processErrorCode(responseCode); lw 9rf4RF
return -2; //-2 represent access is error cY\"{o"C
} i/WiSwh:
8Ow0A
XB-l[4?
String sHeader; be{tyV
< {dV=
naKB2y]l
for(int i=1;;i++) 2(sq*!tX
{ 5l(Q#pSX
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ) bGzsb1\
//Utility.log(in.readLine()); q\6ZmKGnT
sHeader=httpConnection.getHeaderFieldKey(i); Lv?e[GA
if(sHeader!=null) )OcG$H NK
{ *l4`2eqZ
if(sHeader.equals("Content-Length")) Kf7v_T/
{ ~/kx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (|<.7K N
break; vy330SQPo
} QZ51}i
} qy|si4IU8,
else JdeGQ
break; O:,Fif?;
} ]):kMRv
} .FXn=4l'vV
catch(IOException e){e.printStackTrace ();} DN;An0 {MK
catch(Exception e){e.printStackTrace ();} ?rgk
^aG=vXK`b
uEKa FRm
Utility.log(nFileLength); Tb6c]?'U
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return nFileLength; 7 V+rQ
} ?]L:j
\;smH;m
wmr8[n&c
//保存下载信息（文件指针位置） ^yB>0/{)z
private void write_nPos() U$(AZ|0
{ (GdL(H#IL
try{ \hwz;V.J"
output = new DataOutputStream(new FileOutputStream(tmpFile)); x GHS
output.writeInt(nStartPos.length); RGim):1e
for(int i=0;i<nStartPos.length;i++) "Aq-H g
{ jFBnP,WQ
// output.writeLong(nPos); o!+jPwEU
output.writeLong(fileSplitterFetch.nStartPos); R\wG3Oxol
output.writeLong(fileSplitterFetch.nEndPos); lx&ME#~
} 7Q9zEd"d
output.close(); \WeGO.i-
} LMvsYc~]q
catch(IOException e){e.printStackTrace ();} yXx}'=&!0
catch(Exception e){e.printStackTrace ();} Wg+fT{[f|
} j.@TPf*
to
'j+J?Y^
//读取保存的下载信息（文件指针位置） A"@C }f
private void read_nPos() {6yiD
{ Dab1^H!KT
try{ =K)au$BE|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); GUyc1{6
int nCount = input.readInt(); EI29;
nStartPos = new long[nCount]; $iA`_H`W
nEndPos = new long[nCount]; v&EHp{8Qd
for(int i=0;i<nStartPos.length;i++) 3Yd)Fm
{ yU(k;A-
nStartPos = input.readLong(); YrR}55V,
nEndPos = input.readLong(); Uv06f+P(
} e_BOzN~c
input.close(); >#RXYDd
} =kspHP<k
catch(IOException e){e.printStackTrace ();} =y/VrF.bV
catch(Exception e){e.printStackTrace ();} Tl!}9/Q5E:
} h.6yI
WlnI`!)d
U9KnW]O%"
private void processErrorCode(int nErrorCode) ,&sBa{0
{ K6.*)7$#
System.err.println("Error Code : " + nErrorCode); "(+>#
} 46dh@&U
K/y#hP
*}\!&Zk"
//停止文件下载 [lsr[`SJ<
public void siteStop() q lL6wzq,
{ Iky'x[p,D
bStop = true; ,!f*OWnZ
for(int i=0;i<nStartPos.length;i++) >4.{|0%ut
fileSplitterFetch.splitterStop(); j!;?=s
yS#LT3>l
)h~MIpWR
} a"{tqNc
} ?hS n)
//负责部分文件的抓取 ) tGC&l+?/
**FileSplitterFetch.java o(. PxcD
*/ V$wf;v0d(
package NetFox; ?.:C+*+
}XiS:
J}coWjw`q
import java.io.*; D'>yu"
import java.net.*; 1(Kd/%]{
;&|ja]r
TZq']Z)#
public class FileSplitterFetch extends Thread { :_tsS)Q2m
.( vS/
5M~\'\;
String sURL; //File URL IiACr@[?e
long nStartPos; //File Snippet Start Position :Q\b$=,:
long nEndPos; //File Snippet End Position C,w$)x5kls
int nThreadID; //Thread's ID ztG_::QtG]
boolean bDownOver = false; //Downing is over DB yRP-TH
boolean bStop = false; //Stop identical n2R{$^JxO
FileAccessI fileAccessI = null; //File Access interface }Y5Sf"~M
gUCv#:
,c6ID|\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Gt[!q\^?
{ EeKEw Sg
this.sURL = sURL; S2"p(
this.nStartPos = nStart; laqW {sX^5
this.nEndPos = nEnd; X+{4,?04+
nThreadID = id; cT8jG,+"}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }@V(y9K
} Rtn.cSd
5isejR{r
7[55
public void run() Ku_`F2Q
{ 77OH.E|$
while(nStartPos < nEndPos && !bStop) ,k/*f+t
{ p~28?lYv
-lyT8qZ:(
4.7ePbk[E
try{ S"w$#"EJA
URL url = new URL(sURL); kzGD*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RaAi9b[/S
httpConnection.setRequestProperty("User-Agent","NetFox"); `ejE)VL=8h
String sProperty = "bytes="+nStartPos+"-"; 2_0OSbFv'P
httpConnection.setRequestProperty("RANGE",sProperty); pHY~_^B4&
Utility.log(sProperty); R{3f5**0
z48,{H6h
j3~:\H
InputStream input = httpConnection.getInputStream(); LI?rz<H!D
//logResponseHead(httpConnection); o\8yYX
0?ZJJdI3
j ij:}.d6
byte[] b = new byte[1024]; ekfD+X
int nRead; "-vm=d~\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }}Eko7'^
{ }(dhXOf\q
nStartPos += fileAccessI.write(b,0,nRead); Fp-d69Npo
//if(nThreadID == 1) Ud:v3"1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rU5gQq;
} (M6B$:
OUe@U;l{Z
Rw*l#cr=.
Utility.log("Thread " + nThreadID + " is over!"); &D uvy#J
bDownOver = true; IyYC).wU}
//nPos = fileAccessI.write (b,0,nRead); T<DQi
} _I~W!8&w>
catch(Exception e){e.printStackTrace ();} CO1D.5
} 1A">tgA1
} ,~gY'Ql
o8RagSIo8
[a5L WW
//打印回应的头信息 NZ'S~Lr
public void logResponseHead(HttpURLConnection con) ~jmHzFkQ
{ ld4QhZia
for(int i=1;;i++) eM+]KG)}
{ xe2Ap[Y'M
String header=con.getHeaderFieldKey(i); _;{n+i[
if(header!=null) "a;JQ:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k#ED#']N
Utility.log(header+" : "+con.getHeaderField(header)); Q! ]
else v-X1if1%
break; 4)-LlYS_d<
} ;p/RS#
} G1vWHa7n;f
91r#lDR
myFjw@
public void splitterStop() Z= dEk`
{ ^x4I
bStop = true; ZyT9y
} m ,)4k&d
"kz``6C
E:(flW=
} ^:\|6`{n
0eQyzn*98
rcPP-+XW
/* W{At3Bfy
**FileAccess.java 0CQ\e1S,#
*//文件访问(定位，写) 1Qtojph
package NetFox; &n6mXFF#>P
import java.io.*; V(A6>0s$|
7<oLe3fbM
vN-#Ej. u
public class FileAccessI implements Serializable{ v1QE|@
fnG&29x
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 I7nt<l!
RandomAccessFile oSavedFile; *;(LKRV
long nPos; ioIUIp+B~u
L=Fm:O'#2
# h]m8
public FileAccessI() throws IOException ea=@r Ng
{ /fWVgyW>6
this("",0); 1 +O- g
} Ti!j
D!ToCVos
/);cl;"
public FileAccessI(String sName,long nPos) throws IOException f:GZb?Wyd
{ dOqn0Z
oSavedFile = new RandomAccessFile(sName,"rw"); DHW;*A-
this.nPos = nPos; DT8|2"H
oSavedFile.seek(nPos); >0=`3X|Y7
} tEf_XBjKV
3lqR(Hh3
V{O,O,*
public synchronized int write(byte[] b,int nStart,int nLen) .%h.b6^
{ B9/x?Jv1
int n = -1; '%yWz)P
try{ * 'WzIk2
oSavedFile.write(b,nStart,nLen); } '.l'%
n = nLen; #qGfo)
} ;+g p#&i`
catch(IOException e) :Oo(w%BD]
{ /-b)`%Q|Y
e.printStackTrace (); KY<>S/
} B@Ez,u5
+#}I^N
7@$Hua,GY
return n; |Ma"B4
} 13I 7ah
{j+w|;dZF
p\wE})mu
} # nwEF QA
AdesR-e$R
DmM<Kkg.J
/* lplEQ]J|
**SiteInfoBean.java WLQm|C,
*/ P&V,x`<Z
package NetFox; mEmznA
_$s9o$8$
L"&j(|{
public class SiteInfoBean { XL>cTM
'^'vafs-/@
".O+";wk
private String sSiteURL; //Site's URL 3XYCtp8
private String sFilePath; //Saved File's Path a?.hvI
private String sFileName; //Saved File's Name J4#t1P@Na
private int nSplitter; //Count of Splited Downloading File f ."bq43(
~C6d5\
?1K|.lr
public SiteInfoBean() 3xWeN#T0
{//nSplitter的缺省值为5 v}!eJzeH
//default value of nSplitter is 5 Zj99]4?9
this("","","",5); 8 sZ~3
} \Y_2Z/
FN NEh
!jL|HwlA
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) UB }n=
{ v=EV5#A
sSiteURL= sURL; 0'wB':v
sFilePath = sPath; qvy~b
sFileName = sName; cu5Yvp
this.nSplitter = nSpiltter; "jH=O(37
"G-} wt+P
\/g.`Pe
} L!Iu\_{q
eEePK~%c
<RS@,
public String getSSiteURL() laG@SV
{ l&S2.sC
return sSiteURL; 5:6as^i:b
} v*SSc5gFG
AA"?2dF
obKWnet
public void setSSiteURL(String value) LFvKF.
{ zs<W>gBq
sSiteURL = value; (=}cc
} Mo\LFxx>4{
v=zqj}T
:'9%~q.D4
public String getSFilePath() HpSmB[WF
{ o?$kcI4
return sFilePath; ]ppi962Z
} y.AVH`_u
\Z-T)7S
kRo dC(f @
public void setSFilePath(String value) 4NT zK
{ _\hZX|:]
sFilePath = value; G=W!$(:
} ~s{yh-B
^m.QW*
3o&PVU?Q
public String getSFileName() j/`-x
{ :Fz;nG-G
return sFileName; ?piv]Z
} {</MC`
4bLk+EY4A
SIv8EMGo
public void setSFileName(String value) "jqC3$DKI
{ >Ig%|4Hw
sFileName = value; LW<DhMV
} 7^7Rk
g+;)?N*j
47>IT
public int getNSplitter() /` 891(f,
{ 20750G
return nSplitter; Oa~|a7`o
} MG)wVS<d_
M>W-lp^3
,3l=44*
public void setNSplitter(int nCount) Kk#g(YgNz
{ Pw i6Ly`
nSplitter = nCount; ]L#6'|W
} 7?a@i;E<
} T\ZWKx*#
D%GB2-j R
^j&'2n@9a
/* /nEt%YYh;x
**Utility.java mL/]an@Y
*/ g"vg {Q
package NetFox; =<mpZ'9gW
lc9aDt
Jlw%t!Kx
public class Utility { b*Ny
0f~7n*XH
u=NpL^6s<
public Utility() 2<HG=iSf
{ Z0*Lm+d9z
y57]q#k
CBw/a0Uck
} EV{kd.=f
'{=dEEi
//线程睡眠 1-[~}
public static void sleep(int nSecond) gM_z`H5[!
{ R\k= CoJJ
try{ pwo5Ij,~q
Thread.sleep(nSecond); ?&#z3c$}
} KNT(lA0s
catch(Exception e) a)J3=Z-
{ #v!(uuq,
e.printStackTrace (); EOJk7
} "{>I5<:t
} %"tLs%"7=P
.2?txOKh
//日志 k[lYdk
public static void log(String sMsg) EQZu-S`kv
{ d~+8ui{-U
System.err.println(sMsg); 8m,PsUp7
} qjcy{@ j
2,,zN-9mt
9Fb|B
public static void log(int sMsg) fFP>$
{ T \%{zz_(
System.err.println(sMsg); s`"o-w\$>
} [P,YW|:n
} C@+"d3
3GVE/GtU
)9'eckt
/* %-ih$ZY
**TestMethod.java l%"[857
*/ k^3 ?Z2a
package NetFox; Z#7T!/28
*:t]|$;E\
i!8 o(!I
public class TestMethod { ~5Wr |qg%{
'Gwa[ |6i
wn*<.s
public TestMethod() 0l-m:6
{ ///xx/weblogic60b2_win.exe ghvF%-."1
try{ mNkS!(L6
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,4dES|)sP
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?"MJ'u
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6<0-GD}M
fileFetch.start(); +g36,!q
} S%KY%hUt
catch(Exception e){e.printStackTrace ();} *p!K9$4
bz!9\D|h
hKq <e%oVH
} W\09hZ6
r~q*E'n
s+Qm/ h2
public static void main(String[] args) Mazjn?f
{ }`k >6B
new TestMethod(); i8R.Wl$l
} 8joJe>9VJ
} +$i-"^
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