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)); Tw%1m
} 4TQmEM,
for(int i=0;i<nEndPos.length-1;i++) 5`}za-
{ 3J8>r|u;1'
nEndPos = nStartPos[i+1]; ;j~%11
} TUGD!b{
nEndPos[nEndPos.length-1] = nFileLength; ?t}s3P!Q3w
} c#u_%*
} /J"fbBXwY
;9#W#/B
k!z.6di
//启动子线程 `o9:6X?RA
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @D["#pe,}
for(int i=0;i<nStartPos.length;i++) rkh%[o9"/
{ J7dHD(R8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %H_-`A`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q|VBH5}1O
nStartPos,nEndPos,i); o3GZcH?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'lEIwJV$
fileSplitterFetch.start(); GM8>u O
} "Ar|i8^G3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5D-as9k*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); O\oRM2^u}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ETH ($$M
nEndPos = " + nFileLength); e&A3=a~\s
// fileSplitterFetch[nPos.length-1].start(); m'G=WO*%
lHliMBSc
$6ucz'
//等待子线程结束 !z:j-gT3
//int count = 0; xe.f]a
//是否结束while循环 #5^OO ou|
boolean breakWhile = false; l7<VHz0b
~ e<,GUx(]
2t0VbAO1{
while(!bStop) 2w~Vb0
{ z 36Y/{>[
write_nPos(); &{#6Z
Utility.sleep(500); lR F5/
breakWhile = true; S<*1b 6%D
4v(?]]X
q)@;8Z=_c
for(int i=0;i<nStartPos.length;i++) 9)[)07
{ |Ul4n@+2
if(!fileSplitterFetch.bDownOver) U5F1m]gFr
{ S,'ekWVD
breakWhile = false; AjO{c=d
break; GsD?Z%t~%
} cdI"=B+C\
} E+ XR[p
if(breakWhile) Dl\0xcE
break; gH"aMEC
6Y.k<oem
fI.X5c>WK
//count++; ignOF
//if(count>4) uzp\<\d-t
// siteStop(); 5YUe>P D
} ^"uD:f)
{q&`B
<P*7u\9&
System.err.println("文件下载结束！"); ]g%HU%R-m
} wk=s3^
catch(Exception e){e.printStackTrace ();} od!s5f!
} uc=u4@.>
D-m%eP.
xkkG#n)
//获得文件长度 IG%x(\V-e
public long getFileSize() ^Y8G}Z|
{ 11!4#z6w
int nFileLength = -1; daf-B-
try{ <BdC#t:*L
URL url = new URL(siteInfoBean.getSSiteURL()); i1HO>X:ea
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J|z' <W
httpConnection.setRequestProperty("User-Agent","NetFox"); p@?(m/m$
c[C(3c|n
sI4 FgO
int responseCode=httpConnection.getResponseCode(); An BM*5G
if(responseCode>=400) Aq$o&t
{ 7i=ER*F~
processErrorCode(responseCode); LG?b]'#
return -2; //-2 represent access is error \x_$Pu
} '?$<k@mJW
4LJOT_
tK\$LZ
String sHeader; S! .N3ezn
g(F2IpUm/
,(+ZD@Rg
for(int i=1;;i++) grDz7\i:
{ `ih#>i_&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); RS7J~Q
//Utility.log(in.readLine()); n8&x=Z}Xs
sHeader=httpConnection.getHeaderFieldKey(i); MR* %lZpB
if(sHeader!=null) w#sP5qKv8
{ J=#9eW
if(sHeader.equals("Content-Length")) 1n$
{ y8|}bd<Sr
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <FvljKuq+
break; (j}edRUnB
} =?hbi]
} KeC&a=HL
else ~HBx5Cpi
break; wY7+E/
} ,0n=*o@W
} c{/KkmI
catch(IOException e){e.printStackTrace ();} B=i%Z_r]w
catch(Exception e){e.printStackTrace ();} ,\PTn7_
2u}ns8wn
5=.mg6:
Utility.log(nFileLength); &([yI>%
Sr6?^>A@t
.@Jos^rxgJ
return nFileLength; CWE^:kr6
} h)?Km{u%
p/jAr+XM
rGSi !q
//保存下载信息（文件指针位置） `Jl_'P}
private void write_nPos() -k3WY&9,
{ Now2ad&
try{ Qlhm:[
output = new DataOutputStream(new FileOutputStream(tmpFile)); C2K<CDVw
output.writeInt(nStartPos.length); 1++Fs
for(int i=0;i<nStartPos.length;i++) n,|YJ,v[
{ ;:ocU?
// output.writeLong(nPos); vg[zRWh8
output.writeLong(fileSplitterFetch.nStartPos); A@I3:V
output.writeLong(fileSplitterFetch.nEndPos); ?h ym~,
} -k@Uo(MB
output.close(); `>{S?t<
} Z ,98
catch(IOException e){e.printStackTrace ();} izr 3{y5
catch(Exception e){e.printStackTrace ();} ~fly6j|u
} )0 i$Bo
d>1#|
@|Hx>|p
//读取保存的下载信息（文件指针位置） ~RnBs`&!
private void read_nPos() >tV:QP]Y
{ c}#(,<8X
try{ \&%y4=y<sE
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); z_9qT"vF
int nCount = input.readInt(); O9MBQNwjA
nStartPos = new long[nCount]; hHqsI`7c
nEndPos = new long[nCount]; AG,;1b,:81
for(int i=0;i<nStartPos.length;i++) W:=CpbwENX
{ /Oa.@53tK6
nStartPos = input.readLong(); Y]HtO^T2
nEndPos = input.readLong(); ;JR_z'<
} %v1*D^))
input.close(); ;WsV.n
} kv?j]<WN
catch(IOException e){e.printStackTrace ();} bR|1*<
catch(Exception e){e.printStackTrace ();} ("j*!Dsd
} n(el
3O'X;s2\d
\G &q[8F\
private void processErrorCode(int nErrorCode) N!=Q]\ZD
{ :vy./83W
System.err.println("Error Code : " + nErrorCode); ,zrShliU
} ?anKSGfj
jTq@@y
-`e`U%n
//停止文件下载 &5;y&dh
public void siteStop() Pr^p ^s
{ vD4<G{
bStop = true; 'O]Ja-
for(int i=0;i<nStartPos.length;i++) Ry iS
fileSplitterFetch.splitterStop(); o[CjRQY]P
r=pb7=M#LN
HA%r:Px
} $ *^E
} )v?-[ oR
//负责部分文件的抓取 .TWX,#
**FileSplitterFetch.java @](\cT64i3
*/ H(Q|qckj
package NetFox; HxH=~B1"P
(-rw]=Qu
2VNfnk
import java.io.*; B3|rO
import java.net.*; lw"5p)aB
y[@<goT
E8.xmTq
public class FileSplitterFetch extends Thread { -a$7b;gF
M.R]hI
aF\?X&|
String sURL; //File URL HR83{B21
long nStartPos; //File Snippet Start Position a0ze7F<(
long nEndPos; //File Snippet End Position ~h*p A8^L
int nThreadID; //Thread's ID m}3POl/*j
boolean bDownOver = false; //Downing is over R7 *ek_
boolean bStop = false; //Stop identical Q35/Sp[;x
FileAccessI fileAccessI = null; //File Access interface p;rGaLo:u
Z"fnjH
'qg q8
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException zl!`*{T{
{ _}B:SM
this.sURL = sURL; h8!;RN[
this.nStartPos = nStart; ){oVVLs
this.nEndPos = nEnd; -cHX3UAEI
nThreadID = id; h7S&tW GU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mJ|7Jc
} @pD']=d}t
L){rv)?="
o= %Fh
public void run() +$+'|w
{ ZkJYPXdn?
while(nStartPos < nEndPos && !bStop) 1!E+(Iq
{ &n:F])`2
vx\h Njb
Z<#beT6
try{ 5)yQrS !{:
URL url = new URL(sURL); TvWhy`RQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .#;;pu7W
httpConnection.setRequestProperty("User-Agent","NetFox"); Tdr^~dcQ
String sProperty = "bytes="+nStartPos+"-"; ntSPHK|'
httpConnection.setRequestProperty("RANGE",sProperty); D>O{>;y[
Utility.log(sProperty); 3a4 ]{
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j]"Yzt~u
InputStream input = httpConnection.getInputStream(); Dc[Qu?]LM
//logResponseHead(httpConnection); &0 VM <
eD, 7gC-
15r<n
byte[] b = new byte[1024]; >Tld:
int nRead; 5}R/C{fs
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) qb ^4G
{ zy#E qv
nStartPos += fileAccessI.write(b,0,nRead); Kk~0jP_B9
//if(nThreadID == 1) Wv"[,5 Z13
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [j5^Zb&0
} VPf*>ph=
(*%+!PS
fwIZr~l
Utility.log("Thread " + nThreadID + " is over!"); P,O9On
bDownOver = true; Y:VM5r)
//nPos = fileAccessI.write (b,0,nRead); P$@5&/]
} C/[2?[
catch(Exception e){e.printStackTrace ();} 4kA/W0 VG
} S&V5zB""n
} / vge@bsE
^n<p#0)+a
QH4nb h4
//打印回应的头信息 7fl'nCo\"
public void logResponseHead(HttpURLConnection con) >;QkV6i7
{ awXL}m[_!
for(int i=1;;i++) +6f5uMKUvs
{ $<]y.nr|CX
String header=con.getHeaderFieldKey(i); ;2}0Hr'|
if(header!=null) :f^O!^N
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Gn;eh~uw;l
Utility.log(header+" : "+con.getHeaderField(header)); e9q/[xMi
else -b(:kAwStk
break; 0pu])[P]_[
} |zvxKIW;wd
} {:Z#8dGe
qEf)TW(
f b_tda",}
public void splitterStop() @^;WC+\0
{ (XRj##G{
bStop = true; _hMVv&$
} {TdKS
!HqIi@>8
w])bQ7)
} E[htNin.B~
: Ot\l
rg_-gZl8&z
/* & HphE2 h
**FileAccess.java $z{HNY*2
*//文件访问(定位，写) [gzw<b:`
package NetFox; B{/Pv0y
import java.io.*; C3bZ3vcW$
#JO#PV%
9T|7edl
public class FileAccessI implements Serializable{ nf/iZ &
mbd
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~@BV
RandomAccessFile oSavedFile; 4m#i4
long nPos; %MbjKw
)Ah
WqY:XE+?\
public FileAccessI() throws IOException RURO0`^
{ ^lRXc.c z
this("",0); ^67P(h
} A~nq4@uj
BIbcm,YQ
Cl<`uW3
public FileAccessI(String sName,long nPos) throws IOException PM=I
{ wxo(
oSavedFile = new RandomAccessFile(sName,"rw"); } %S1OQC
this.nPos = nPos; !S%XIq}FX
oSavedFile.seek(nPos); S][:b
} ]ueq&|
Lkk'y})/
<LZvG IMl
public synchronized int write(byte[] b,int nStart,int nLen) t ~U&a9&Z
{ r]BB$^@@V
int n = -1; AZl|; y
try{ 4^70r9hV9
oSavedFile.write(b,nStart,nLen); 7F\U|kx_
n = nLen; wzo-V^+q
} &ks>.l\
catch(IOException e) X[NsdD?w1+
{ .__X[Mzth3
e.printStackTrace (); \+Qx}bS{
} q*Ns]f'a
{U^mL6=&v
,a^_ ~(C
return n; y7d)[d*Mz
} q+gqa<kM
G:u[Lk#6K
SRM[IU
} z6'zNM7M
!ybEv| =
Lk#u^|Eq7=
/* &giJO-^ f
**SiteInfoBean.java j]Rl1~+M
*/ 'cH),~ z
package NetFox; Q(Vc/
!c(B^E
w`>xK sKW>
public class SiteInfoBean { ;EL!TzL:8
QhpE2ICU
z<^HohT
private String sSiteURL; //Site's URL 2$[u&__E
private String sFilePath; //Saved File's Path 68 -I2@&
private String sFileName; //Saved File's Name hs<7(+a
private int nSplitter; //Count of Splited Downloading File ;\Wg>sq
8.Y6r
/Pg66H#RUf
public SiteInfoBean() L8R|\Bx
{//nSplitter的缺省值为5 zq{L:.#ha
//default value of nSplitter is 5 3@ay9!Xq
this("","","",5); =x/]2+ s
} &)xoR4!2
O%0G37h
rf)\:75
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J#:%| F%
{ J,{sRb%
sSiteURL= sURL; Rq4\~F?
sFilePath = sPath; H1hj` '\"<
sFileName = sName; P}?,*'b
this.nSplitter = nSpiltter; L2Gm0 v
x,>@IEN7
3ufUB^@4v
} #<v3G)|aS
{CQA@p:Y}
lW^RwNcd
public String getSSiteURL() q7m-} mBN~
{ s{IycTbz
return sSiteURL; U&`M G1uHe
} oWx! 'K6]V
@xO<~
5<ery~q
public void setSSiteURL(String value) Dyt}"r\
{ tOp>OoD
sSiteURL = value; /A<L
} ']}ZI 8
c(YNv4*X
+uv]dD*i
public String getSFilePath() Sfh\4h$H
{ 6I_W4`<VeZ
return sFilePath; V/762&2X
} 4V<s"
iSIj ?.
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public void setSFilePath(String value) Xv=n+uo
{ <A"}Krq?
sFilePath = value; Z$HYXm
} ;uDH&3W
OU0\xx1/
(B,CL222x
public String getSFileName() uF@Q8 7G
{ `C] t2^
return sFileName; 0Ba-VY.H
} oD~VK,.
9<\wa/#
^aXyho
public void setSFileName(String value) yy/wSk
{ 1 ljgq]($
sFileName = value; !cp ,OrO\
} JBi<TDm/
GaM#a[p
hD # Yz<
public int getNSplitter() M<g>z6
{ ]|~],\
return nSplitter; (K^9$w]tf
} J%3S3C2*m
BE}lzn=sF
@ZD1HA,h"
public void setNSplitter(int nCount) ihf5`mk/$
{ />K$_T/]
nSplitter = nCount; IqcPml{\
} c%Kv"Z%f
} 8Ay#6o
vL\wA_z"<H
sT'wps2
/* H:y.7
**Utility.java f>-OwL($P
*/ QZt/Rm>W0
package NetFox; OHM.xw*?.
i nF&Pv
B.0(}@
public class Utility { X:@nROL^7
)bw^!w)
IkL|bV3E0
public Utility() >vt#,8VAN
{ ~*THL0]~
H@,jNIh~h
o&fAnpia=
} /|`;|0/2
WLv( K_3Y
//线程睡眠 u+z$+[lm!G
public static void sleep(int nSecond) Pm7,Nq)<>n
{ P0k|33;7L
try{ l J;wl|9
Thread.sleep(nSecond); i2)rDek3]T
} >umcpkp-h
catch(Exception e) Y-gjX$qGo
{ y<8)mw
e.printStackTrace (); n M,m#"AI
} -:*PXu
} kIP~XV~
ATk>:^n
//日志 dkLc"$(O
public static void log(String sMsg) fPZBm&`C
{ )=[K$>0k
System.err.println(sMsg); Xr6lYO_R
} gB71~A{J
P\*-n"
8!4=j
public static void log(int sMsg) ~}$:iyJV(>
{ T{{J' _s5L
System.err.println(sMsg); +mMn1&
} < 5;0LPU
} -r/#20Y
bhnm<RZ
>"5^]o2?~l
/* )PB&w%J
**TestMethod.java @@'zMV%
*/ LV4x9?&
package NetFox; M5: f^
FWq6e,
gE`G3kgn{
public class TestMethod { ;!Ojb
05=O5<l
aVO5zR./)
public TestMethod() `a3q)}*Y
{ ///xx/weblogic60b2_win.exe (GMKIw2
try{ ^qIp+[/'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %0Ulh6g;Dt
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V7[Dvg:W
SiteFileFetch fileFetch = new SiteFileFetch(bean); NA]7qb%%<
fileFetch.start(); DN&ZRA
} zi:GvTG
catch(Exception e){e.printStackTrace ();} 7h&$^
/FkLZm
i>7f9D7
} Kbg`ZO*
4+$<G/K
>XSe[K
public static void main(String[] args) E@JxY
{ ]6pxd \Q
new TestMethod(); nAoGG0$5
} ^ B=x-G.
} c^6v7wT5
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