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)); .$d:c61X
} `0W"[BY
for(int i=0;i<nEndPos.length-1;i++) `lm'_~=`&
{ ":T"Y;
nEndPos = nStartPos[i+1]; MY\mo,#
} aBQ--Sz
nEndPos[nEndPos.length-1] = nFileLength; &<#1G u_
} ,0HID:&
} ;W+1 H !
:#sBNy
kz1Z K
//启动子线程 qooTRqc#,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; n&]J-^Tx
for(int i=0;i<nStartPos.length;i++) Z>w@3$\z
{ B (h`~pb
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hC{2LLu;n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), E{-pkqx
nStartPos,nEndPos,i); f]2gjQHM
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zN9@.!?X2
fileSplitterFetch.start(); MwD+'5
} ~ cu+QR)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c uAp,!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); K4NzI9@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", liB~vdqj
nEndPos = " + nFileLength); ^cW{%R>XY
// fileSplitterFetch[nPos.length-1].start(); .'+JA:3R
b)XGr?
ZA_~o#0%
//等待子线程结束 p+Bvfn
//int count = 0; >>R)?24,<
//是否结束while循环 ;1,#rTs
boolean breakWhile = false; +LWgby4q
# 6?2 2Os
GQ.akA_(
while(!bStop) KVoi>?a
{ YP"%z6N@v
write_nPos(); u0+<[Ia'q
Utility.sleep(500); )('{q}JxV
breakWhile = true; T3)m{gv0`
`+KLE(]vyH
?|2m0~%V=
for(int i=0;i<nStartPos.length;i++) m^0*k|9+G
{ ?~}8^~3
if(!fileSplitterFetch.bDownOver) A1zV5-E/
{ o'P[uB/
breakWhile = false; JP]4* l
break; w+%p4VkA<r
} Y\1& Uk
} rY6bc\?`x
if(breakWhile) Oh`Pf;.z%
break; z;YX2G/{
Y'6P ~C;v
u4=ulgi
//count++; hoPh#? G
//if(count>4) .b*-GWx
// siteStop(); JKXIxw>q
} _#P5j#
eBECY(QMQ
CS"k0V44}
System.err.println("文件下载结束！"); 1*@Q~f:Uk
} wE <PXBl\b
catch(Exception e){e.printStackTrace ();} M@.?l=1X
} :e_yOT}}
T5-'|+
|>I4(''}
//获得文件长度 %s%e5hU
public long getFileSize() QmPHf*w[
{ 5FNf)F
int nFileLength = -1; p_3VFKq>0
try{ mxvV~X%
URL url = new URL(siteInfoBean.getSSiteURL()); a5g1.6hF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 79lG~BGE
httpConnection.setRequestProperty("User-Agent","NetFox"); ?0E-Lac=
/8(t:
IP1{gMG
int responseCode=httpConnection.getResponseCode(); Ce3
if(responseCode>=400) !.{{QwZ
{ i6h0_q8 >
processErrorCode(responseCode); 6ozBU^n
return -2; //-2 represent access is error w$I$xup
} ?v@q&
);F /P0P
\l;H!y[
String sHeader; D>q?My
[;INVUwG^
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for(int i=1;;i++) E"H>[E
{ ;{>-K8=>$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U &W}c^#
//Utility.log(in.readLine()); Cd'SPaR
sHeader=httpConnection.getHeaderFieldKey(i); dG]s_lb9H
if(sHeader!=null) kmL~H1qd
{ Vuo 8[h>
if(sHeader.equals("Content-Length")) {[B`q
{ iuq%Q\0@w
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); pK2n'4 C
break; _UeIzdV9
} nr9cG/"
} k{$Mlt?&-
else 6sRKbp|r7
break; Uw_z9ZL
} T/l2B1
} .mS'c#~5Y
catch(IOException e){e.printStackTrace ();} #T)gKp
catch(Exception e){e.printStackTrace ();} Ne,u\q3f
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{~d8_%:b
Utility.log(nFileLength); }NJ? .Y
Vt,"5c
I:#Es.
return nFileLength; nR~L$Wu5_a
} (hX}O>
_\xd]~ELj
xSHeP`P^X
//保存下载信息（文件指针位置） [R[Suf
private void write_nPos() F{aM6I
{ GwVSRI:[N
try{ AfW9;{j&I
output = new DataOutputStream(new FileOutputStream(tmpFile)); }h)[>I(
output.writeInt(nStartPos.length); bQM_rqjJGw
for(int i=0;i<nStartPos.length;i++) |[lM2
{ 3~!PJI1
// output.writeLong(nPos); R'r^v
output.writeLong(fileSplitterFetch.nStartPos); \=/^H
output.writeLong(fileSplitterFetch.nEndPos); Me*]Bh
} KIUa
output.close(); vl}uHdeP9
} pn~$u
catch(IOException e){e.printStackTrace ();} Y|iALrx
catch(Exception e){e.printStackTrace ();} PUViTb
} rj].bGQ,+
#nh;KlI0
^^Tu/YC9x
//读取保存的下载信息（文件指针位置） pb5'5X+
private void read_nPos() N^.!l_
{ rx#\Dc}
try{ 3l@={Ts
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0zAj.iG
int nCount = input.readInt(); L);kwx7{LW
nStartPos = new long[nCount]; \YBY"J
nEndPos = new long[nCount]; q,a|lH
for(int i=0;i<nStartPos.length;i++) f[/E $r99J
{ #_bSWV4
nStartPos = input.readLong(); `cr.C|RT:
nEndPos = input.readLong(); S)*eAON9
} Qy@r&
input.close(); o5FBqt
} obE_`u l#
catch(IOException e){e.printStackTrace ();} q|%(47}z
catch(Exception e){e.printStackTrace ();} ^\<1Y''
} GZ];U]_
(HkMubnqg
A%s"WSx,
private void processErrorCode(int nErrorCode) 7Jm9,4]
{ BI]%$rq
System.err.println("Error Code : " + nErrorCode); eS jXaZh
} *lIK?"mo
f13%[RA9N
3RP}lb
//停止文件下载 YDyi6x,
public void siteStop() %!HmtpS
{ r,x;q
bStop = true; *qE[Y0Cd
for(int i=0;i<nStartPos.length;i++) f&Bu_r
fileSplitterFetch.splitterStop(); of^N4
; . c]0
bd2"k;H<o
} `1KZ14K
} .;n<k
//负责部分文件的抓取 T%xB|^lf
**FileSplitterFetch.java |:tFQ.Z'2
*/ h2Z Gh
package NetFox; 08S|$_
f[!QR
SL/ FMYdd
import java.io.*; O(otI-Lc
import java.net.*; j%KLp4J/e
SA|f1R2uS
16YJQ ue
public class FileSplitterFetch extends Thread { QP?Z+P<
.Tdl'y:..
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String sURL; //File URL ,bCPO`45
long nStartPos; //File Snippet Start Position mMw&{7b:
long nEndPos; //File Snippet End Position U&/Jh^Yy
int nThreadID; //Thread's ID 9\i,3:Qc
boolean bDownOver = false; //Downing is over B" wk:\zC
boolean bStop = false; //Stop identical UGPD5wX?
FileAccessI fileAccessI = null; //File Access interface It4J\S
Kl$!_$
pVw)"\S%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Q<r O5 -K
{ b#.hw2?a`
this.sURL = sURL; -iS\3P.
this.nStartPos = nStart; u[^(s_
this.nEndPos = nEnd; oZ@_o3VG
nThreadID = id; Y2w 9]:J
fileAccessI = new FileAccessI(sName,nStartPos);//定位 gBq,So
} %?C{0(Z{
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kO\(6f2|x
public void run() JF_\A)<ki
{ 5sx-u!7
while(nStartPos < nEndPos && !bStop) t_WNEZW7f
{ l0b Y
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1DGVAIcD
try{ ~/hP6*
URL url = new URL(sURL); Ni GK|Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1z$;>+g<
httpConnection.setRequestProperty("User-Agent","NetFox"); "S^;X @#v
String sProperty = "bytes="+nStartPos+"-"; h]c-x(+
httpConnection.setRequestProperty("RANGE",sProperty); >ea<6&!Ee
Utility.log(sProperty); ~-6Kl3Y
A[!Fg0X0
Hi9;i/
InputStream input = httpConnection.getInputStream(); RIM"MR9qe=
//logResponseHead(httpConnection); |]]Xee]
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NQ{ XIN~
byte[] b = new byte[1024]; p/'C v
int nRead; w=3@IW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \p.Byso,
{ DCmNxN
nStartPos += fileAccessI.write(b,0,nRead); ID5?x8o#k
//if(nThreadID == 1) *KFsO1j
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >NW /0'/
} M\8FjJ>9
+8Zt<snG
q=}Lm;r
Utility.log("Thread " + nThreadID + " is over!"); :j vx-jQ
bDownOver = true; ?ae:9ZcH
//nPos = fileAccessI.write (b,0,nRead); 2:/'
} M&y!w
catch(Exception e){e.printStackTrace ();} #=b_!~:%
} 6U7z8NV&[
} I [0od+K
F1)Q#ThF\
,$sq]_t
//打印回应的头信息 Sy'/%[+goJ
public void logResponseHead(HttpURLConnection con) ev#d1s|<S
{ M{:gc7%
for(int i=1;;i++) WUdKj
{ *6q8kQsz^1
String header=con.getHeaderFieldKey(i); \y: 0+s/
if(header!=null) QO7> XHn
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Yq#I# 2RD
Utility.log(header+" : "+con.getHeaderField(header)); y^hpmTB3"
else 9ToM5oQ
break; J~DP*}~XK
} 7~eo^/PbS
} -Z<e`iFQS
n@5pS3qZ
KcfW+>W3
public void splitterStop() )~O{jd
{ wQp,RpM
bStop = true; JXGIVH?Rpu
} iX.=8~3
Rmn|"ZK
X!CLOHVAa
} Q{H88g^=J
\h :Rw|
X`:(-3T
/* xp1 +C{
**FileAccess.java *WfOB2rU
*//文件访问(定位，写) -t?S:9[w
package NetFox; g;\zD_":l
import java.io.*; e&7GW9FSg
x7l)i!/$
\"_;rJ{!aE
public class FileAccessI implements Serializable{ 5cxA,T
iyu%o9_0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @*q\$Eg}2
RandomAccessFile oSavedFile; Gc4N)oq)}b
long nPos; A!<R?
9 o-T#~i
H4KwbTT"+
public FileAccessI() throws IOException E[nWB"pxE
{ =9YyUAJZ
this("",0); lV`y6{o#T
} !o:RIwS3
}^?dK3~q
68Wm=j.m
public FileAccessI(String sName,long nPos) throws IOException 6H VS0
{ v=i[s
oSavedFile = new RandomAccessFile(sName,"rw"); 7SXi#{
this.nPos = nPos; |j^>6nE
oSavedFile.seek(nPos); (Y, @-V
} t{!}^{ "5
emw3cQ
/.$n>:XR
public synchronized int write(byte[] b,int nStart,int nLen) @6 gA4h
{ !F;W#Gc
int n = -1; 0$}+tq+
try{ uc=-+*D'I
oSavedFile.write(b,nStart,nLen); 0l.+yr}PE
n = nLen; W5_t/_EWD
} 4'Vuhqk
catch(IOException e) #rzxFMA"
{ R7x4v
e.printStackTrace (); *J8j_-i,R
} 2y ~]Uo
eAu3,qoM
#R305
return n; 3r+vpyu
} =o{zw+|% %
Z?XE~6aP>
vj[ .`fY
} $62ospR^Y
V`S6cmwdc\
GZXUB0W\@)
/* l K}('7\
**SiteInfoBean.java L;fhJ~r
*/ +X cB5S>
package NetFox; q^([ & +
K}`.?6O
kIrME:
public class SiteInfoBean { qK.8^{b
jf*M}Q1jHE
zg)Z2?K|;u
private String sSiteURL; //Site's URL t \DS}3pv
private String sFilePath; //Saved File's Path V2i*PK X
private String sFileName; //Saved File's Name U,[vfSDGr
private int nSplitter; //Count of Splited Downloading File rbO9NRg>
9"=:\PE
B\KvKT|\
public SiteInfoBean() , YTuZS
{//nSplitter的缺省值为5 `Kpn@Xg
//default value of nSplitter is 5 Sw%=/g
this("","","",5); Xy_+L_h^
} Z7K;~*
vs7Hg)F
C[& \Xq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) EtcAU}9
{ _;v4]MU
sSiteURL= sURL; k/j]*~"
sFilePath = sPath; r<UZ\d -
sFileName = sName; x}AWWmXv
this.nSplitter = nSpiltter; y*vs}G'W
HS="t3
TN.mNl%
} A$;U*7TJuO
eMPi ho
xo6-Y=c8
public String getSSiteURL() p r(:99~3
{ tL 3]9qfj
return sSiteURL; 2e/ JFhA
} DFVaZN?~
^7Z)/c`"
jU@qQ@|
public void setSSiteURL(String value) $ze%!C
{ -PBm@}*
sSiteURL = value; ,m8l /wG
} xs.>+(@|;
Br`Xw^S
&]ts*qCEL
public String getSFilePath() ]6GdB3?UVM
{ &Jk0SUk MP
return sFilePath; 8JJqEkQ
} s34{\/'D+
Gi6sl_"q
h-<('w:A
public void setSFilePath(String value) 5^ARC^v
{ ^UEI`_HO0
sFilePath = value; t}c ymX~
} i"0^Gr
% E3
Owo2DsT t
public String getSFileName() |k^'}n
{ =v:vc~G6
return sFileName; ht(RX
} =n cu#T]
8l~]}2LAs
L1VUfEG-
public void setSFileName(String value) Ha[Bf*
{ d2Z5HFtY
sFileName = value; 4sP0oe[h
} PL@hsZty~c
)c^Rc9e/
8uP,#D<wZ
public int getNSplitter() K;k_MA310
{ /$|C s
return nSplitter; 4;<?ec(dc
} W.r0W2))(
z4HIDb
eY-W5TgU
public void setNSplitter(int nCount) Xjw>Qws
{ &-:ZM0Fl
nSplitter = nCount; WUvrC
} Mi%i_T^i
} r?nvJHP
@mSdksB/L
X#EMmB!
/* T&oY:1D,g
**Utility.java [ %cW ?@
*/ s{(aW5$!s
package NetFox; cV\(Z6u
3=RVJb
|F=!0Id<
public class Utility { YiJnh47
({v$!AAv
^ |z|kc
public Utility() O:IU|INq8
{ ai)S:2
Ew5(U`]
j1Fy'os"!
} uUB,OmLN
umaF}}-Q{
//线程睡眠 Dq/_^a/1
public static void sleep(int nSecond) )a AKO`
{ -*~= 4m<
try{ |]1-ck!
Thread.sleep(nSecond); i,r O3Jn
} z#ab V1 Xi
catch(Exception e) P"Lk(gY
{ wzVx16Rvc
e.printStackTrace (); B7zyMh
} 4nK\gXz19
} {;4Y5kj
)e(Rf!P{
//日志 UbNA|`H
public static void log(String sMsg) jfP2n5X83
{ \3JZ=/
System.err.println(sMsg); m\o<a|
} %X7R_>.
Y~gDS^8
d[E~}Dq3#
public static void log(int sMsg) }Qyuy~-&^
{ ~P8 6=Vw
System.err.println(sMsg); ^,*ED Yz
} `Fnl<C<
} t2skg
!~Gx@Ro
:)o 4fOJ8
/* O=~8+sa
**TestMethod.java ZKy)F-yX
*/ s~ ||Vv!
package NetFox; nr7#}pzo
Yv<'QC
]L+YnZ?6
public class TestMethod { PP)iw@9j
RfH.WXi
~QgyhJM_h=
public TestMethod() TRP#b 7nC
{ ///xx/weblogic60b2_win.exe q.0Evr:
try{ !~Vo'ykwx'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;wo
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); POvxZU
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8=QOp[w
fileFetch.start(); x93h{Kf
} Zk,` Iq
catch(Exception e){e.printStackTrace ();} kt`_n+G
BIGln`;,f
mN^w?R41m
} jz,Mm,Gi
`_%UK=m
_gU:!:}
public static void main(String[] args) 8Na.H::cZ
{ !%MI9Ok
new TestMethod(); V`P8oIOh]
} ]Z\Z_t
} f@S n1c,Mk
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