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)); aNn"X y\ k
} w]b,7QuNz
for(int i=0;i<nEndPos.length-1;i++) 9E2j!
{ i,A#&YDl
nEndPos = nStartPos[i+1]; `p b5*h6r!
} %J:SO_6
nEndPos[nEndPos.length-1] = nFileLength; {rfF'@[
} \<Sv3xy&O
} uwf 5!Z:>
@vL20O.
&AVpLf:?
//启动子线程 tWTKgbj(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^D^4 YJz
for(int i=0;i<nStartPos.length;i++) ]5~s"fnG
{ S##1GOO
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4n#ov=)-~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Xs&TJ8a
nStartPos,nEndPos,i); 2?m.45`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "mL++>ZSQ
fileSplitterFetch.start(); iwz
} ^-FX
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iGB_{F~t4}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g%F"l2M
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l`kWz5[~
nEndPos = " + nFileLength); J q{7R
// fileSplitterFetch[nPos.length-1].start(); -jgysBw+Xb
q~CA0AR
26X+ }^52
//等待子线程结束 DeR='7n
//int count = 0; ]E =Iu
//是否结束while循环 ?USQlnr:R/
boolean breakWhile = false; !fBF|*/
%Qg+R26U
9/+Nj/
while(!bStop) m}>F<;hQ
{ vR0];{
write_nPos(); 2G$SpfeIu
Utility.sleep(500); m<L;
breakWhile = true; OD']:
1&fc1uYB4
%uv?we7
for(int i=0;i<nStartPos.length;i++) "V{yi!D{<
{ .jy]8S8[|%
if(!fileSplitterFetch.bDownOver) %|G"-%_E
{ hhoEb(BA
breakWhile = false; Ltjbxw"Qd
break; iNwqF0
} wP"dZagpj
} NBb6T V}j
if(breakWhile) Mi~(aah
break; %e*@CbO$
=2w4C_
|yo\R{&6
//count++; gWY"w!f
//if(count>4) A.UUW
// siteStop(); p&VU0[LIC0
} jD7NblX
9W5onn
wf1lyS
System.err.println("文件下载结束！"); =)|-?\[w
} >vo=]cw
catch(Exception e){e.printStackTrace ();} tE7[Smzuf
} :x_'i_w
&S{RGXj_
bhTb[r
//获得文件长度 &gVN&
public long getFileSize() we~[] \
{ +%zAQeb
int nFileLength = -1; 7E r23Q
try{ V+* P2|
URL url = new URL(siteInfoBean.getSSiteURL()); 4ni<E*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #C~+JL
httpConnection.setRequestProperty("User-Agent","NetFox"); rq8K_zp
aktU$Wbwl
AF;)#T<
int responseCode=httpConnection.getResponseCode(); B8.Pn
if(responseCode>=400) ] bM)t<
{ 6}gls}[0{e
processErrorCode(responseCode); 1L%CJ+Q#0i
return -2; //-2 represent access is error 8##-EN;ag
} #a/5SZP Z\
wa<MRt W=
E ]A#Uy
String sHeader; lGV0*Cji
/f:dv?!km
=)M/@T
for(int i=1;;i++) Hu\B"fdS
{ R0P iv:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); nOt&pq7
//Utility.log(in.readLine()); zvYq@Mhr
sHeader=httpConnection.getHeaderFieldKey(i); yh Yb'GK
if(sHeader!=null) s>B5l2Q4
{ j`JMeCG=Ee
if(sHeader.equals("Content-Length")) V, Z|tB^
{ s1MErd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,~aQL
break; [;r)9mh7
} 1t:Q_j0Ym
} ;kFDMuuO
else *;l]8.
break; H7z,j}l
} p#01gB
} 09X01X[
catch(IOException e){e.printStackTrace ();} ,V,`Jf
catch(Exception e){e.printStackTrace ();} ^!<U_;+
l7XUXbYp&=
03|PYk 6EW
Utility.log(nFileLength); \l'm[jy>
eV2W{vuI
#+:9T/*>0
return nFileLength; %}SGl${-
} 0ZT5bg_M
MuYk};f
;+e}aER&9
//保存下载信息（文件指针位置） O!mvJD
private void write_nPos() 5QW=&zI`=
{ `_BNy=`s*
try{ fL_4uC i\
output = new DataOutputStream(new FileOutputStream(tmpFile)); wg7V-+@i
output.writeInt(nStartPos.length); zcel|oz)
for(int i=0;i<nStartPos.length;i++) @GBxL*e
{ Sc>,lIM
// output.writeLong(nPos); S'|,oUWDb
output.writeLong(fileSplitterFetch.nStartPos); ?zeJ#i
output.writeLong(fileSplitterFetch.nEndPos); ^WHE$4U`
} o>).Cj
output.close(); @E;=*9ek{u
} 4iqoR$3Fc
catch(IOException e){e.printStackTrace ();} LIS)(X<]?
catch(Exception e){e.printStackTrace ();} 9%8"e>~
} *EOdEFsR/
?^H `M|S
_g+JA3sIJ
//读取保存的下载信息（文件指针位置） Vu)4dD!
private void read_nPos() |*oZ_gI
{ ))R5(R
try{ q+Lr"&'Q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t|H^`Cv6
int nCount = input.readInt(); cQ/5qg
nStartPos = new long[nCount]; R{WE\T'
nEndPos = new long[nCount]; !Z`j2 e}
for(int i=0;i<nStartPos.length;i++) aUzBV\Yd}
{ w&$`cD
nStartPos = input.readLong(); 1_o],?Q
nEndPos = input.readLong(); fRrvNj0{V
} w:%o?pKet1
input.close(); hXfQ)$J
} H(R1o~
catch(IOException e){e.printStackTrace ();} I CZ4A{I
catch(Exception e){e.printStackTrace ();} VYu~26Zr
} XF Patd
UM!ENI|
bHPYp5UwN
private void processErrorCode(int nErrorCode) CUO+9X-<8
{ EqyeJq .
System.err.println("Error Code : " + nErrorCode); K-e9>fmB#
} sc|_Q/`\.
o]+z)5zC
3[\iQ*d }B
//停止文件下载 J{l1nHQZSu
public void siteStop() )hd@S9Z.Y
{ 0@yXi
bStop = true; o4`hY/<t
for(int i=0;i<nStartPos.length;i++) /mXBvY
fileSplitterFetch.splitterStop(); ,`wXg
!,l9@eJQ
m#8m] Y
} c|lu&}BS
} ?Y)vGlWDW<
//负责部分文件的抓取 tkVbo.[8K
**FileSplitterFetch.java pA`+hQNN
*/ nA?`BOe(
package NetFox; hhSy0
XUM!Qv
VcAue!MN
import java.io.*; *YW/_
import java.net.*; stG~AC
8;z6=.4xtg
IYqBQnX}oM
public class FileSplitterFetch extends Thread { @En^wN
g3Ec"_>P
Mx6@$tQ%
String sURL; //File URL M^MdRu
long nStartPos; //File Snippet Start Position {n(b{ibl
long nEndPos; //File Snippet End Position ;6gDV`Twy
int nThreadID; //Thread's ID jYx38_5e
boolean bDownOver = false; //Downing is over -#0qV:D
boolean bStop = false; //Stop identical tna .52*/
FileAccessI fileAccessI = null; //File Access interface ]p*l%(dhY
V\6=ySx
VOKZ dC-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p%iGc<vHX
{ 3Dg,GaRk
this.sURL = sURL; WzAb|&?
this.nStartPos = nStart; JCz@s~f\y
this.nEndPos = nEnd; F ;{n"3<
nThreadID = id; .EpV;xq}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Cnnh7`
} E>&n.%
%dJX-sm@
7x#Ckep:I
public void run() gG uZ8:f
{ <!L>Exh&r
while(nStartPos < nEndPos && !bStop) bQE};wM,
{ k xP-,MD
uJOJ-5}yt
(H)2s Y
try{ 0rh]]kj
URL url = new URL(sURL); |w_7_J2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WEFlV4/
httpConnection.setRequestProperty("User-Agent","NetFox"); I{ HN67O
String sProperty = "bytes="+nStartPos+"-"; r9X?PA0f
httpConnection.setRequestProperty("RANGE",sProperty); Ae mDJ8Y
Utility.log(sProperty); J+[_Wd
"nZ*{uv
wyp|qIS;
InputStream input = httpConnection.getInputStream(); )u3 Zm
//logResponseHead(httpConnection); 0*%Z's\M"
iDMJicW!+F
:r%P.60H X
byte[] b = new byte[1024]; nNrPHNfqD
int nRead; #rxVd 7f
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =Qh\D
{ NXwz$}}Pp
nStartPos += fileAccessI.write(b,0,nRead); W4hbK9y
//if(nThreadID == 1) Z&0'a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N U|d
} UjaK&K+M?
Dpvk\t
#6ri-n
Utility.log("Thread " + nThreadID + " is over!"); Uh7v@YMC
bDownOver = true; =.y~fA!
//nPos = fileAccessI.write (b,0,nRead); D<|qaHB=
} e"/;7:J5\
catch(Exception e){e.printStackTrace ();} ]x\-$~E
} eK.e|z|
} j2Tr$gx<
>"gf3rioW
W4[V}s5u
//打印回应的头信息 )A!>=2M`
public void logResponseHead(HttpURLConnection con) (EK"V';
{ ZaeqOVp/j
for(int i=1;;i++) *_R]*o!W'
{ [E+$?a=
String header=con.getHeaderFieldKey(i); HHiT]S9
if(header!=null) W- i&sUgy
//responseHeaders.put(header,httpConnection.getHeaderField(header)); RMd[Yr2e
Utility.log(header+" : "+con.getHeaderField(header)); ?dD&p8{
else h]og*(
break; 4$qWiG~
} ELBa}h;
} i7ISX>%
, FhekaA
'6Ay&A3N]
public void splitterStop() >2~+.WePu
{ uvtF_P/
bStop = true; .{44a$)
} *F ?8c
U"q/rcA
)E6;-rD0^+
} b`)){LR
m_=$0m J$
^dP KDrKxh
/* *:>"q ej
**FileAccess.java =:DaS`~V
*//文件访问(定位，写) -QOw8vm
package NetFox; {LX.iH9}l
import java.io.*; [QMu2
Sl-v W
Ul2R'"FB
public class FileAccessI implements Serializable{ ._8KsuJG
A]YVs
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \]P!.}nX#
RandomAccessFile oSavedFile; _Dym{!t
long nPos; ^&bRX4pYo
vr0WS3
, #U.j
public FileAccessI() throws IOException @?=|Y
{ 1U^A56CN
this("",0); YhOlxON
} WA]c=4S
]Tkc-ez
N-I5X2
public FileAccessI(String sName,long nPos) throws IOException 2R=DB`3
{ bhkUKxd
oSavedFile = new RandomAccessFile(sName,"rw"); SG-'R1 J
this.nPos = nPos; }:u~K;O87
oSavedFile.seek(nPos); FL(6?8zK
} (S xR`QP?,
Mu{;vf|j
Nc+,&R13m
public synchronized int write(byte[] b,int nStart,int nLen) o4*+T8[|5
{ ;3\3q1oX
int n = -1; w;k):;$
try{ >Y_*%QGH_
oSavedFile.write(b,nStart,nLen); c6nflk.l
n = nLen; tjGd )
} OR}c)|1
catch(IOException e) H|RT?Q
{ PZ{Dv'C
e.printStackTrace (); KN7^:cC
} K$M^gh0
qw@puw@D
U+)xu>I
return n; 3dht!7/
} _<a7CCg
9uRFnzJVx
BT)X8>ct
} D[_|*9BC
-8r
~><^'j[
/* T:/,2.l
**SiteInfoBean.java 3 n'V\Hvz
*/ SfJ./ny
package NetFox; }?z@rt^
0Z0:,!
8zA=;~GHP
public class SiteInfoBean { ?;vgUO
uL3Eq>~x
" R-!(9k^`
private String sSiteURL; //Site's URL = M]iIWQ@`
private String sFilePath; //Saved File's Path UB 6mqjPK
private String sFileName; //Saved File's Name K'X2dG*
private int nSplitter; //Count of Splited Downloading File A5i:x$ww
~zSCg|"r
@+9<O0
public SiteInfoBean() %^1cyk
{//nSplitter的缺省值为5 ,WvY$_#xW%
//default value of nSplitter is 5 v^zu:Z*
this("","","",5); oP!;\a( SL
} -O&CI)`;B
E2cB U{x
oS7(s
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \3'9Uz,OC
{ aX~%5mF
sSiteURL= sURL; AX= 1b,s
sFilePath = sPath; abJ" [
sFileName = sName; AJSx%?h:6
this.nSplitter = nSpiltter; qTAc[Ko
~mO62(8m
&g.@u~SI1
} C4hx@abA
={5#fgK>
lW(px^&IN
public String getSSiteURL() c>/. ;p
{ ~v'3"k6
return sSiteURL; 'v\L @"
} 7zHh@ B:]
jCrpL~tWT
H|ER
public void setSSiteURL(String value) 6I!7c^]t
{ :=8t"rO=W
sSiteURL = value; em\ 9'L^
} Ea?XT&,
W -
Mz1G5xcl
public String getSFilePath() ?V}j`r8|\4
{ YKE46q;J
return sFilePath; nK$X[KrV'
} 7<jZ`qdq_
/Nr*`l
E@-KGsdhK
public void setSFilePath(String value) 1fo U
{ >0dv+8Mn
sFilePath = value; @#P,d5^G
} !!4Qj
Xe#K{gA
m!W3Cwz\&
public String getSFileName() t9Y=m6
{ u~3%bJ]
return sFileName; \=0Vuz
} f)g7 3=
m85WA # `
{0;3W7
public void setSFileName(String value) rz"txN
{ kl"+YF5/
sFileName = value; Up:<=Kgci
} &AlJ "N|
01T`Flz
I+!:K|^
public int getNSplitter() = pI?A^
{ +3a?`Z
return nSplitter; :> &fV
} MwfOy@|N
avy"r$v_&
<,AS8^$X[
public void setNSplitter(int nCount) %0 #XPc("
{ ATy*^sc&"
nSplitter = nCount; })w*m
} gtYAHi
} >Bs#Xb_B]
O:{U^K:*
[w\9as/ E
/* |A%<Z(
**Utility.java t6BHGX{o
*/ DfV~!bY
package NetFox; ?88`fJ@tk?
EwS!]h?
U:MPgtwe
public class Utility { O$kq`'9
XyMG.r-,
>HPdzLY?
public Utility() j F-v%?
{ `xiCm':
+fx8muz:y
Mc-)OtmG[
} k8,?hX:
341?0%=
//线程睡眠 _U{([M>;
public static void sleep(int nSecond) x f4{r+
{ 5'w^@Rs5
try{ hUz[uyt
Thread.sleep(nSecond); |0{u->+ )
} 83cW=?UgA
catch(Exception e) aZKOY
{ =SD\Q!fA
e.printStackTrace (); X%bFN
} YpUp@/"
} W>M~Sk$v
* MM[u75
//日志 $6F)R|
public static void log(String sMsg) Y${l!+q
{ V@d)?T
System.err.println(sMsg); CK_(b"
} \n9A^v`F/
;nmM7TZ;
\Hqc9&0
public static void log(int sMsg) >x3ug]Bu
{ gPzL*6OSA
System.err.println(sMsg); @c'|Iqy`
} ~#}Dx :HH
} <DH*~tLp2
i`)!X:j
tvX>{-M
/* ZyR_6n>L$
**TestMethod.java z"DkFvA
*/ A>NsKWf{
package NetFox; ,jy*1Hjd
}a&mY^
R7~Yw*#,
public class TestMethod { V 'X;jC
:L0/V~D
Lc<eRVNd,
public TestMethod() oUx[+Gnv
{ ///xx/weblogic60b2_win.exe rZbEvS
try{ %Y4e9T".
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); OMihXt[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Uz%Z&K
SiteFileFetch fileFetch = new SiteFileFetch(bean); J NC
fileFetch.start(); n,P5o_^:
} iy\KzoB
catch(Exception e){e.printStackTrace ();} 17hTr
/T0nLp`gi
K#K\-TR|$
} Aox3s?
e=/&(Y
0;~yZ?6_F
public static void main(String[] args) dMl+ko
{ K8^kJSF\
new TestMethod(); ly4Qg\l
} 0"xPX#Cvj
} rFJ[dz
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