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)); bF|j%If%
} g5; W6QX
for(int i=0;i<nEndPos.length-1;i++) Ex&f}/F
{ %kKe"$)0
nEndPos = nStartPos[i+1]; &owBmpz
} l`[*b_ Xt
nEndPos[nEndPos.length-1] = nFileLength; B&O931E7
} m%qah>11
} PfF7*}P
UyEyk$6SU
hz>&E,<8q
//启动子线程 _;G"{e.=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b_W0tiyv%
for(int i=0;i<nStartPos.length;i++) vp[~%~1(
{ .NiPaUzc<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UpN:F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (`<l" @:_*
nStartPos,nEndPos,i); )o SFHf
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Me`jh8(K\6
fileSplitterFetch.start(); &t5pJ`$(Cy
} O<)"kj 7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z>wg o@z%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <6Y o%xt
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", c03A_2%
nEndPos = " + nFileLength); 4 "@BbVYR
// fileSplitterFetch[nPos.length-1].start(); .%M=dL>
S^c5
RI')iz?
//等待子线程结束 Q|"{<2"]U0
//int count = 0; cPPE8}PVH
//是否结束while循环 1Ty{k^%
boolean breakWhile = false; `N_NzH
o/CSIvz1
u f.Zg;Vc
while(!bStop) %$~?DDNM
{ Hh(_sewo
write_nPos(); /IxMRi=
Utility.sleep(500); 4["$}O5
breakWhile = true; di "rvw;R
z%hB=V!~91
V+nqQ~pJ&
for(int i=0;i<nStartPos.length;i++) :05>~bn>pC
{ .o]vjNrd/
if(!fileSplitterFetch.bDownOver) *QG>U[
{ BikmAa
breakWhile = false; eg3zpgZ
break; ME>OTs
} $83TA><a
} ']Nw{}eS`
if(breakWhile) 3R !Mfz*
break; V/.Y]dN5
51*o&:eim
l=Jbuc
//count++; &s_[~g<
//if(count>4) HfFP4#C,
// siteStop(); >Yl?i&3n
} '%. lY9D
b*no.eB
gLaFIeF<+
System.err.println("文件下载结束！"); _Su? VxU
} XTG*56IzL
catch(Exception e){e.printStackTrace ();} zbOEF
} qq]ZkT}
LR@rn2Z
-|~6Zf"
//获得文件长度 DDwH9*
public long getFileSize() nBgksB*A
{ ?}D@{%O3T
int nFileLength = -1; 5sao+dZ"|
try{ m;>HUTj
URL url = new URL(siteInfoBean.getSSiteURL()); ZL:nohB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _bHmcK
httpConnection.setRequestProperty("User-Agent","NetFox"); JpvE c!cli
63#Sf$p{v
&y[Od{=
int responseCode=httpConnection.getResponseCode(); j="{^b
if(responseCode>=400) c*'D
{ po}Jwx!
processErrorCode(responseCode); [>A%%
return -2; //-2 represent access is error fLa 7d?4
} !_QE|tVeR
.RxH-]xk
n-be8p)-
String sHeader; *r6+Vz
2ro4{^(_
f]tc$`vb
for(int i=1;;i++) [[}KCND
{ Du k v[/60
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $z"3_4a
//Utility.log(in.readLine()); vrXUS9i.
sHeader=httpConnection.getHeaderFieldKey(i); i(Cd#1<
if(sHeader!=null) 02g}}{be8
{ _Jn-#du
if(sHeader.equals("Content-Length")) T\eOrWt/
{ t4R=$ km
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); aze}koNE
break; Ms;:+JI
} bF;g.-.2
} +!\$SOaR{
else K9\`Wu_qL
break; 3R1v0
} Cu3^de@h
} GS_'&Yj
catch(IOException e){e.printStackTrace ();} 3Kc
catch(Exception e){e.printStackTrace ();} ?B.>VnYZ/a
R*lJe6
'#mv-/<t*
Utility.log(nFileLength); ma)Y@Uw M
Q|q.~x<RQ
I,OEor6%R(
return nFileLength; h[b;_>7
} L=nyloz,0
LE%3.. !
6}ct{Q
//保存下载信息（文件指针位置） QCIH1\`jW
private void write_nPos() DF|(CQs9
{ -.~Dhk
try{ S 'S|k7Lp
output = new DataOutputStream(new FileOutputStream(tmpFile)); Lt$LXE
output.writeInt(nStartPos.length); `?+lM
for(int i=0;i<nStartPos.length;i++) (%=[J/F/
{ ~:~-AXaMT
// output.writeLong(nPos); I?}YS-2
output.writeLong(fileSplitterFetch.nStartPos); 0"]N9N;/
output.writeLong(fileSplitterFetch.nEndPos); ;^za/h>r
} M >#kfSF+
output.close(); >0z(+}]3z
} e~w-v"'
catch(IOException e){e.printStackTrace ();} 7SOi9JU_
catch(Exception e){e.printStackTrace ();} r)UtS4 7
} _yw]Cacr\
#q'J`BC
r8x<-u4
//读取保存的下载信息（文件指针位置） x?v/|
private void read_nPos() Z+!._uA
{ =:OS"qD3l
try{ V+j58Wuf
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); V+myGsr`
int nCount = input.readInt(); ejP273*ah
nStartPos = new long[nCount]; 4n_f7'GZg
nEndPos = new long[nCount]; mcvd/
for(int i=0;i<nStartPos.length;i++) D=uU:7m
{ EUZ#o\6
nStartPos = input.readLong(); 2MaHD}1Jw
nEndPos = input.readLong(); f}Mx\dc
} ?*lpu
input.close(); mxUM&`[
} Khp`KPxz%
catch(IOException e){e.printStackTrace ();} k`ulDQu
catch(Exception e){e.printStackTrace ();} u hW@ Y+
} r!A1Sfo4P
P/uk]5H^
`IL''eJug_
private void processErrorCode(int nErrorCode) \@8j&],dl
{ Rg@W0Bc)
System.err.println("Error Code : " + nErrorCode); C{AVV<
} WfYu-TK*
*F7ksLH|q
7~(|q2ib
//停止文件下载 l>p S23
public void siteStop() |t](4
{ sTeW4Hnp
bStop = true; !jZXh1g%
for(int i=0;i<nStartPos.length;i++) ,?s3%<\2
fileSplitterFetch.splitterStop(); $*a'[Qot#
80=6B
7`AQn],
} }Fy~DsQ
} Hq=5/N
//负责部分文件的抓取 X.TsOoy
**FileSplitterFetch.java 8Ac5K!
*/ 9,8}4Y=GVI
package NetFox; 92zo+bc
C8 [W
Z#w@ /!"}T
import java.io.*; 0G@sj7)]
import java.net.*; ?VVtEmIN
_4H 9rPhf
Reci:T(_
public class FileSplitterFetch extends Thread { cZ>h[XX[
o9&&u1`M/
kaybi 0
String sURL; //File URL cF6eMml;
long nStartPos; //File Snippet Start Position -UD^O*U
long nEndPos; //File Snippet End Position }?^V9K-
int nThreadID; //Thread's ID =P>c1T1-
boolean bDownOver = false; //Downing is over cbsU!8
boolean bStop = false; //Stop identical |-kU]NJFR
FileAccessI fileAccessI = null; //File Access interface 3!]S8Y*LQP
)y8 u+5^
8)n799<.
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException o\ss
{ s'/b&Idf8
this.sURL = sURL; |j3fS[.$
this.nStartPos = nStart; k4WUfL d
this.nEndPos = nEnd; wCT. (d_
nThreadID = id; a W1y0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 L#)F00/`
} u!wR
FwD"Pc2
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public void run() E=PmOw7b
{ -1^dOG6*
while(nStartPos < nEndPos && !bStop) dS9L(&
{ YXeL7W
EtVRnI@
ue?e}hF
try{ ]r6S|;:
URL url = new URL(sURL); +v$,/~$tI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DK-V3}`q}
httpConnection.setRequestProperty("User-Agent","NetFox"); k.UQT^.
String sProperty = "bytes="+nStartPos+"-"; >SS YYy
httpConnection.setRequestProperty("RANGE",sProperty); ZY NHVR
Utility.log(sProperty); p%MH**A
/"$A?}V
u/W
InputStream input = httpConnection.getInputStream(); PDwi])6mf
//logResponseHead(httpConnection); CVo2?ZQ
II=(>G9v
vE4ce
byte[] b = new byte[1024]; 8cN[t.S
int nRead; 4rpx
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) mBb;:-5
{ Yfro^}f
nStartPos += fileAccessI.write(b,0,nRead); _wvSLu<q
//if(nThreadID == 1) w0`aW6t#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _T[7N|'O
} iv3=J
Rwu y!F
2h Wtpus
Utility.log("Thread " + nThreadID + " is over!"); A}./ ;[
bDownOver = true; \J@i:J6x$1
//nPos = fileAccessI.write (b,0,nRead); |ATz<"q>
} WX2:c,%:
catch(Exception e){e.printStackTrace ();} 3}U {~l!K
} ?ks3K-.4
} @(k}q3b<
2@&|/O6_\h
RXo!K iQO
//打印回应的头信息 j%7N\Vb
public void logResponseHead(HttpURLConnection con) tXlo27J
{ 1Z. D3@
for(int i=1;;i++) hT c VMc
{ gmFCjs
String header=con.getHeaderFieldKey(i); ;;A8*\*$
if(header!=null) ):LgZ4h
//responseHeaders.put(header,httpConnection.getHeaderField(header)); P~"e=NL5
Utility.log(header+" : "+con.getHeaderField(header)); 4<P=wK=a8X
else u1@&o9
break; HLD8W8
} -o\o{?t,
} xbZx&`(
16;r+.FB'
n2e#rn
public void splitterStop() U/9i'D[|{
{ "4`i]vy8
bStop = true; 5"5tY
} Nn`l+WA3
P1gW+*?
YU*u!
} QL_vWG-
xEULV4Qw
}8joltf
/* C2l=7+X#W
**FileAccess.java 2N)siH
*//文件访问(定位，写) PTt#Ixn,
package NetFox; .mr&zq
import java.io.*; >M2~BDZ
7yUtG^'b
@y"/hh_?
public class FileAccessI implements Serializable{ DQ#rZi3I
df85g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8[PD`*w
RandomAccessFile oSavedFile; 3e)W_P*0?
long nPos; t[dOWgHi
;7;=)/-
+-s$Htx
public FileAccessI() throws IOException eUY/H1
{ { :^;byd
this("",0); -k4w$0)
} R]LRgfi9
5ov F$qn
D7X8yv1
public FileAccessI(String sName,long nPos) throws IOException N9SC\
{ 6}(;~/L
oSavedFile = new RandomAccessFile(sName,"rw"); %a'Nf/9=:
this.nPos = nPos; <`PW4zSI
oSavedFile.seek(nPos); a/@F?\A
} !Dc|g~km\
V:YN!
bi@z<Xm%
public synchronized int write(byte[] b,int nStart,int nLen) :!'!V>#g
{ +n'-%?LD&
int n = -1; FZk=-.Hk
try{ %ZKP d8
oSavedFile.write(b,nStart,nLen); ?QJS6i'k
n = nLen; hggP9I:s,
} IasWm/
catch(IOException e) d ynq)lf
{ 5{PT
e.printStackTrace (); /i[1$/*
} b6]MJ0do
3dl#:Si
?3duW$`
return n; B.Szp_$
} l?f%2:}m
XCN^>ToD
SV?^i`
} Y&![2o.Q
spX*e1
B(eC|:w[z
/* *wfb~&:}
**SiteInfoBean.java Y<ZaW{%
*/ [iO*t,3@h
package NetFox; I:l/U-b7h
C6PlO
d~|/LR5
public class SiteInfoBean { 8:9/RL\"x
?q*,,+'0
PLV-De
private String sSiteURL; //Site's URL $2kZM4
private String sFilePath; //Saved File's Path ;YfKG8(0
private String sFileName; //Saved File's Name ?D\6@G:,#@
private int nSplitter; //Count of Splited Downloading File m9Pzy^g1
,f[`C-\Q%
3*v&6/K
public SiteInfoBean() Gg,&~ jHib
{//nSplitter的缺省值为5 gP13n!7
//default value of nSplitter is 5 '(6 ^O=
this("","","",5); >V,i7v*?
} Z=I+_p_G
2[V9`r8*
qQ{i2D%)?f
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +YX*.dW
{ U65a_dakk
sSiteURL= sURL; *"HA=-Z;
sFilePath = sPath; > &VY
sFileName = sName; [YTOrN
this.nSplitter = nSpiltter; N!Q~?/!d
g[%iVZ
!vY5X2?tr,
} `Lr I^9Z
_!K@(dl
Qt~QJJN?oF
public String getSSiteURL() &*\-4)Tf
{ 'CfM'f3uu
return sSiteURL; `pJWZ:3
} Py! F
Z/*X)mBuB
LJh^-FQ
public void setSSiteURL(String value) !l7D1i~
{ -*nd5(lY&
sSiteURL = value; HX`>" ?{
} l`b%imX
S [=l/3c
Y@#rGV>
public String getSFilePath() qrLE1b 1$
{ wRCv?D`vV
return sFilePath; :9.QhY)D
} nuucYm%IF-
|%tI!RN):
|9;MP&68
public void setSFilePath(String value) ixjhZki<
{ Mv1V Vk
sFilePath = value; 8j^3_lD
} M!#[(:
#^zUaPV 7r
0Vwl\,7z9
public String getSFileName() hAvX{]
{ 9`| ^cL*6
return sFileName; g+zfa.wQ
} xU(yc}vw,
%AV[vr,
;#+Se,)
public void setSFileName(String value) (\A~SKEX
{ iqAME%m
sFileName = value; >=VtL4K^
} VYAz0H1-_
QZO9CLX 8k
92pl#Igt
public int getNSplitter() qCUn. mI
{ vbMt}bM(GD
return nSplitter; rd0[(-
} t)n}S;iD
[Fo"MeH?R
sR*.i?lN
public void setNSplitter(int nCount) w"/RI#7.
{ rD*CLqK
nSplitter = nCount; ,f3Ck*M
} =(\xe| Q
} ](tv`1A,Wd
O~L/>Ya
iI@m e=
/* {T(z@0Xu
**Utility.java "<^]d~a_
*/ JQdeI+
package NetFox; okSCM#&:[2
a?gziCmS?C
jC3)^E@:"
public class Utility { 8r-'m%l
<}z,!w8
nLjc.Z\Bl
public Utility() .`5BgX7W
{ 4.o[:5'
#CcWsI>+w>
o0`|r+E\
} k,M%"FLQ
|j>fsk~
//线程睡眠 Xx;4
public static void sleep(int nSecond) !^*-]p/z
{ U%zZw)
try{ oHvVZ
Thread.sleep(nSecond); $9In\x
} cpe/GvD5]
catch(Exception e) `xm4?6
{ `GQ'yv
e.printStackTrace (); k2t#O%_f
} Im0#_ \
} J[7|Ul1 <
{I"`(
//日志 9! 6\8
public static void log(String sMsg) ?=^M(TA;
{ H6! <y-
System.err.println(sMsg); iTpU4Qsj
} <&Q(I+^
7$HN5T\!
P3u,)P&
public static void log(int sMsg) 1~_&XNb&
{ w=K!U]
System.err.println(sMsg); c=Y8R/G<
} " +n\0j;
} @!MhVNS_<
/'uFX,
SPEDN}/^
/* [ta3sEPjs
**TestMethod.java @ApX43U(
*/ -|\SNbPTV
package NetFox; 'D1Sm&M2%e
:!nBTw
QZ:xG:qyk;
public class TestMethod { 0A.PfqYi
wO&2S-;_K
++ZtL\h{7
public TestMethod() 6;^ e
{ ///xx/weblogic60b2_win.exe TP-<Lhy
try{ H.R7,'9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2B<0|EGtzw
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ' +*,|;?
SiteFileFetch fileFetch = new SiteFileFetch(bean); (bBr O74lR
fileFetch.start(); KWzJ
} Z.v2!u
catch(Exception e){e.printStackTrace ();} Ag#o&Y
7\e96+j|f
pS C5$a(
} ;{e=Iz}/
|4tnG&=
LG6k KG
public static void main(String[] args) g3"eEg5NY
{ YR$)yl
new TestMethod(); zEu15!~
} &GetRDr
} KE k]<b=
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